1.
If you describe something as ~, you mean that it benefits you in some way, for example by teaching you about something. (FORMAL)
In the 18th century art was seen, along with music and poetry, as something ~.
= instructive
ADJ
2.
You say that something is not very ~ when you want to express your disapproval or dislike of it, or to suggest that there is something unpleasant or unacceptable about it.
It all brought back memories of a not very ~ past.
ADJ: with brd-neg disapproval