They say that the Eskimo have over 50 different words for different types of snow. (They do!)
Then you get to humans and their relationships. On one extreme end, there are people that don’t know each other at all — that’s easy to define: a stranger.
But as you go up the line of types of relationship you get to lots of fuzzy and ill-defined sections. Portions that don’t quite have a definition. Of course, things aren’t even measured on a single dimension either.
We all live in the in-between all the time.
Sometimes a word isn’t needed at all.
It just is.