Basically two things:

1. Definitions
2. Justifications

@tim wood (thanks Harley Davidson) is very particular about both, going through the trouble of educating novices and issuing gentle reminders to veterans on both matters: he even has two/three threads on these topics (use the TPF search feature to find them).

Speaking for myself, I try not to criticize people on these points for the simple reason that I can't tell the difference between bad definitions and unique definitions & bad reasoning from peculiar, idiosyncratic, ergo interesting, reasoning.

More can be said, but my brain's taken a holiday.

This is how we protect ourselves from the following:
[...]

I respect and see your point but I guess it also depends on the context. There are formal and informal conversations. The OP would be helpful when we are debating something related to a serious issue or when the involved members are strangers. But, when you are with friends or in a friendly environment, I think you could use less formal techniques

"What exactly does it mean?" (What does that mean more precisely?)
"How do we know that it is so?" (How do you know that?)

There seems to be another factor implicit in your two questions. What are you referring to by 'meaning'? This could be a reference to personal significance (ex: "The gesture meant so much to me") or to a known system of affects (ex: To fall means to momentarily lose footing and accelerate by gravity), or possibly something else. Your second question, "how do we know that this is so" suggests that your are limiting your scope to an accepted perspective or an finite apparatus. Is true knowledge really a process at all? Certainly we can say there is a process for attaining and validating facts, but I'm not convinced in the necessity of a such a repetitious process for finding knowledge.

1. Definitions
2. Justifications

Might I suggest a third term, 'Significance/Relevance'? Is it enough to know without questioning why that entity wishes to know? Why, for instance, should we give equal weight to a discussion about philosophy and a discussion about the infinity of supernatural and ungrounded things? If we did, we would not have enough time to investigate anything in real depth.

@javi2541997
@kudos

I completely agree with what you are saying.

My point was probably that one also protects oneself emotionally against simplistic abstract monopolizing statements.

Examples:

Christian: Jesus is resurrected and is our only way to salvation. Faith saves.

Kantian: Spatiotemporal structures do not exist per se and whoever lies commits a serious moral offense.

Antinatalist: Life is not worth living, the bad outweighs the good and whoever brings a child into the world commits a crime. Feelings of pleasure are only the absence of feelings of displeasure.

The radical skeptic: You can never be sure if there is an outside world, there might be no reason whatsoever for our having the perceptual experiences we have, truths are always relative, no knowledge can be expressed with language.One can doubt the validity of the contradiction principle.

The misanthrope: All people are bad. Trees have more value than people. Animals are the better people. Mankind belongs to be exterminated.

The Radical Woke: It is shameful to be a white male, one should have deepest compassion for anybody who is not a white male, even if there is no direct suffering.

The climate alarmist: If the whole world doesn't change something radically now, the earth will very soon no longer be habitable.

And so on and so forth.

I think with the two questions I mention, you can quickly contextualize all of these positions and strongly weaken or "debunk" them and not be emotionally affected by them.

What exactly does it mean?" (What does that mean more precisely?)

and

"How do we know that it is so?" (How do you know that?) — spirit-salamander

I generally ask, "What difference does it make?"

In the end, there is a lot of information and detail that actually contributes nothing to knowledge or to a life lived, it's just clever (or not) twaddle.

A key problem with these questions is that they can't be appleid the same by each person, so the results are not just highly variable but inconsistent.

Take God. What exactly does it mean? Well, nothing to me - the idea is incoherent. To my friend the Priest, it means a vocation, a commitment, an ontological certainty.

How do we know it is so? Could hardly be a more divisive question, throwing into relief the presuppositions people hold which makes the question almost pointless.

You can't measure smoke with a ruler.

Etc....

I generally ask, "What difference does it make?" — Tom Storm

That's also a good question. But I would put it in third place.

In the end, there is a lot of information and detail that actually contributes nothing to knowledge or to a life lived, it's just clever (or not) twaddle.

A key problem with these questions is that they can't be appleid the same by each person, so the results are not just highly variable but inconsistent. — Tom Storm

The questions I mention are probably more for one's own intellectual conscience and intellectual probity.

They help to be an educated person, even if it means not knowing much (Socratic), especially when asked in naiveté.

Examples:

Christian: Jesus is resurrected and is our only way to salvation. Faith saves. — spirit-salamander

Meh, I even do not want to ask. This argument looks like empty for me because I am not religious. Probably this statement sounds quite disrespectful. But, what I want to share with you is that it depends how worthy of reading/listening the other part must be.
I quote your other example:

Kantian: Spatiotemporal structures do not exist per se and whoever lies commits a serious moral offense. — spirit-salamander

Exactly, in this context, I would ask:

"What exactly does it mean?" (What does that mean more precisely?)

Because it sounds so interesting and worthy to learn for me

Meh, I even do not want to ask. This argument looks like empty for me because I am not religious. Probably this statement sounds quite disrespectful. — javi2541997

You may have already asked in the past in one form or another and found every answer lacking. But if you had never dealt with Christianity before? Given the spread alone, one might probably have to ask.

But if you had never dealt with Christianity before? — spirit-salamander

But, maybe, I do not need deal with Christianity since the beginning.

Okay, I agree, personal interest plays a big role.

But what do you do when someone confronts you with Christianity? At a party during small talk, or confronted by friends and family?

But what do you do when someone confronts you with Christianity? — spirit-salamander

I going to sound rude as hell but I would ignore him/her. It is difficult to explain but I want to avoid being involved in thoughts I do not believe about. I feel it could be even worthless and a lost of time to me

I feel it could be even worthless and a lost of time to me — javi2541997

Fair enough.

These are the questions that in the end make us an authentically educated person:
"What exactly does it mean?" (What does that mean more precisely?)
and
"How do we know that it is so?" (How do you know that?)
These questions must become our second nature, and we must ask them constantly, tirelessly and fearlessly — spirit-salamander

True enough, but education isn't everything. "I love you." "What exactly do you mean by 'love'? And how do you know when you love someone?" So, perhaps not to be asked 'constantly'. But I'm splitting hairs, it's a good idea.

And so on and so forth. — spirit-salamander

The one who thinks they can see through it all and go to the heart of the matter with intelligent analysis. That's one I have to be particularly aware of and I see him in the mirror too often......

These are the questions that in the end make us an authentically educated person: — spirit-salamander

1. What's the use of being an authentically educated person?

And just for kicks:

2. What exactly is an authentically educated person?

3. How do we know that it is so?

The idea I presented is more or less from a German philosopher named Peter Bieri.

An answer should be in the following translated passage of that same Peter Bieri:

"As far as the idea of education is concerned, it cannot mean: to rule over others with one's knowledge. The power of knowledge lies elsewhere: it prevents one from being a victim. Those who know about the world are less easily fooled and can defend themselves when others want to make them the plaything of their interests, in politics or advertising, for example. Orientation in the world is not the only orientation that matters. To be educated also means to be well versed in the question of what knowledge and understanding consist of, how far they reach and what their limits are. It means asking oneself the question: What do I really know and understand, and what of the things I and others believe is on shaky ground? It means taking a cash-check of knowledge and understanding. This includes questions like these: What evidence do I have for my beliefs? Are they reliable? And do they really prove what they seem to prove? How reliable are the principles used to get from evidence to claims that go beyond it? What are valid inferences, and what are fallacies? What are good arguments, and what is fallacious sophistry? The knowledge to be gained here is second-order knowledge. It distinguishes the naive from the educated scientist, the serious from the simple-minded journalist who has never heard of source criticism. Second-order knowledge saves us from becoming the victim of superstition. When does one event make another probable? What is a law as opposed to a coincidental correlation? What distinguishes a true explanation from a bogus explanation? This is what we need to know if we are going to assess a risk and make a judgment about all the predictions we are bombarded with. Someone who is awake to these things will keep a skeptical distance not only from esoteric literature, but also from economic forecasts, election campaign arguments, psychotherapeutic promises, and brazen presumptions of brain research. And he will become irritated when he hears others merely parroting scientific formulas."

And he will become irritated when he hears others merely parroting scientific formulas. — spirit-salamander quoting Bieri

All good. I share the irritation. In addition, I think there are two traps. The first is to assume that those who reach contradictory conclusions have not also applied the same rigour and the same skeptical distance. They may have done and we might be wrong or we might both be partly right. The second is to assume that those who have clearly not applied this rigour are, for that reason alone, mistaken. They may or may not be. I am talking about the need for epistemic modesty and dialectical charity.

Those who know about the world are less easily fooled and can defend themselves when others want to make them the plaything of their interests, in politics or advertising, for example.

:up: I am agree. Not only in the fact we can be less fooled by press media but the art of increasing our knowledge. I cannot believe there are people who don't care about the world and do not want go further. I think it is a problem. We can't allow the nations to have such ignorant people around. It could be counter-productive, I do not see the point of manipulate the persons in long-term.

Someone who is awake to these things will keep a skeptical distance not only from esoteric literature, but also from economic forecasts, election campaign arguments, psychotherapeutic promises, and brazen presumptions of brain research. And he will become irritated when he hears others merely parroting scientific formulas."

Apart from skeptical thought, I would say pessimism. When we are not easily catfished by others and we can see how vicious men/women can act, we tend to decrease our belief in everything related to the state. Probably this causes the isolation in some persons