Escape? Come off it! (7)
I believe the answer is:
getaway
'escape?' is the definition.
(getaway is a kind of escape)
'come off it' is the wordplay.
I cannot quite see how this works, but
'come' could be 'get' (synonyms) and 'get' is located in the answer.
'off' could be 'away' (synonyms) and 'away' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for getaway that I've seen before include "flight" , "Escape" .)