Plato may have been the first to attempt to define "good"; then G. E. Moore had something of import to say about it. The polymath genius who eventually came up with a precise logical adequate contextual definition of the concept "good" was Dr. Robert S. Hartman. You can read a partial bio about him on Wikipedia. Also there you could find a (somewhat technical) entry touching on Value Science. The article in Wiki doesn't do the topic justice; one needs to read the original writings of Hartman for that. Here I will share with you some material from the opening pages of the first chapter of a booklet I co-authored several years ago. I'll be glad to take any questions on this after you look it over, if you care to consider doing so, or to ask about anything afterwards.
BIW,The booklet is entitled LIVING THE GOOD LIFE. Here is a link to it: - http://wadeharvey.myqol.com/wadeharvey/Living_The_Good_Lifef.pdf

What makes the Good Life good?
Let’s offer some basics. We’ll inquire as to what makes anything good –
for example, a hammer or a telephone call? Then we’ll be in a position
to understand what makes a good life good. We’ll take up four profound
questions here in this chapter: What’s valuable? What does “good”

mean? What’s better? And finally: Are there types of value, some
better than others? All of this will give us a clear understanding of why a life
(or anything else for that matter) has been described as "good."

After that we will be ready to consider the question: Who
is the good life good for? You see, we’d like to take some of the
vagueness and confusion out of these important matters in order to gain
clarity regarding our topic – which is Living the Good Life. So let’s turn
first to the important question, What does the word “value” mean?

Have you ever wondered What’s valuable? Or What do people mean
when they use that term? It wouldn’t hurt to define what we’re talking
about. It might even be helpful. When we use words such as “valuable,”
“good,” and “better,” what do we mean by them? Let’s see.
For an item to be valuable is for it to be meaningful. We call something
valuable when it has some features that the valuer is looking for, or
expecting – else he or she would not call it ‘valuable.’

For example, a valuable hammer will have some of the qualities, some
of the features, that a hammer has in our picture of what a hammer is; a
good hammer will have everything – everything for which we are willing
to settle at the time we grade that hammer. As a hammer it will be full
of (hammer) meaning. It’s the same with ‘a good phone-call.’ And in
the same way, a good life will be a highly-meaningful life.

To be better is to be richer in meaning, to be more valuable: for when we
say this thing is better than that thing we mean this one is more valuable
than that one. Even values themselves can be compared this way. A
better value will be a value that is richer in meaning.

We want to define these words so that later we can discuss “the good
person” and be clear about what we are saying. For, after all, ethics –
which is something everyone should care about – concerns the good
person, and concerns What is the Good Life for the good person? Is a
moral life the good life? Maybe. But what would that mean? Future
chapters will hone in on that subject.

What say you? All intelligent and constructivecomments and questions are welcome.