So I'm led to expect that you think that to sensibly discuss whether a given behaviour is intelligent, friendly or moral, we need to be able to give precise definitions for intelligence, friendship and morality. But I can only think that this is fundamentally misguided: the discussions around these concepts are relevant precisely because we do not have such definitions at hand. We can try to unpack our intuitions about what we think of as a concept, for example by tabooing the word for it. But this is completely different from giving a definition.

Well, morality is such an enormous and multi-sided topic that what usually matters in a concrete situation is only some particular small subset of morality. A discussion can be meaningful if there is agreement on the issue at hand, even if there is disagreement otherwise. So to take the same example again, if we're discussing whether someone is a thief (i.e has committed the sort of immoral behavior that is called "theft"), it doesn't matter if we define murder differently, as long as we define theft the same.

But yes, of course that discussing whether a given behavior is intelligent, friendly, or moral makes sense only if we agree on the definitions of these terms. As I said above, in practice our definitions about human affairs are always fuzzy and incomplete to some degree, so there will always be disagreement at least in some corner cases, and discussions will be meaningful as long as they stick to the broader area of agreement. However, in case of friendship, intelligence, and most issues of morality, people typically agree at least roughly on the relevant definitions, so the usage of these words is usually meaningful.

Also, when people agree on definitions, it doesn't matter if they are able to state these definitions precisely and explicitly, as long as there is no disagreement on whether the definitions are satisfied assuming given facts. Giving a precise definition of "friendship" would be a difficult task for most people, but it doesn't matter since there is no significant disagreement on what behavior is expected from people one considers as friends, and what behavior should disqualify them. One the other hand, when someone makes vague ideological accusations such as "sexism," there is no such agreement at all, and a rational discussion can't even being before a clear definition of the term is given.