Good; tolerable (3,3)
I believe the answer is:
not bad
I believe this clue is a double definition.
'good' is the first definition.
(similar in meaning)
'tolerable' is the second definition.
(I've seen this in another clue)
(Other definitions for not bad that I've seen before include "Acceptable" , "Quite good" , "could be OK" , "fine" , "Informally good, a bit grudging" .)