Nevertheless, time for an idea (7)
I believe the answer is:
thought
'for an idea' is the definition.
('thought' can be a synonym of 'idea')
'nevertheless time' is the wordplay.
'nevertheless' becomes 'though' (I've seen this before).
'time' becomes 't' (abbreviation).
'though'+'t'='THOUGHT'
(Other definitions for thought that I've seen before include "Content of cognition" , "Supposed" , "Deliberated" , "Study" , "just a trifle" .)