satisfactory
The company was judged to be performing satisfactorily.
The mystery was never satisfactorily explained.
Only two of the essays had been completed satisfactorily.

SMART Vocabulary: related words and phrases

Quite good, or not very good
acceptable
acceptably
adequacy
adequate
adequately
goodish
government
half decent
iffy
impure
passable
passably
patchily
patchiness
patchy
scratch
spotty
the/your average bearidiom
up to scratchidiom
weedy