Take old gear (7)
I believe the answer is:
opinion
'take' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'old gear' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'gear' becomes 'pinion ' (pinion is a kind of gear).
'o'+'pinion'='OPINION'
Can you help me to learn more?
(Other definitions for opinion that I've seen before include "Estimation" , "View held without positive proof" , "Personal belief without proof" , "View, barrister's advice" , "Conviction - point of view" .)