Adequate, acceptable (12)
I believe the answer is:
satisfactory
This clue is a double definition.
'adequate' is the first definition.
(similar in meaning)
'acceptable' is the second definition.
(I know that acceptable can be written as satisfactory)
(Other definitions for satisfactory that I've seen before include "Up to scratch" , "Fully acceptable" , "Fulfilling expectations" , "fine" , "unexceptional" .)