With gin, rest, we hear, in bar at circus? (7)
I believe the answer is:
trapeze
'bar at circus?' is the definition.
'with gin rest we hear' is the wordplay.
I cannot really see how this works, but
'gin' could be 'trap' (I've seen this before) and 'trap' is present in the answer.
This may be the basis of clue (or it may be nonsense).
'in' is the link.
(Other definitions for trapeze that I've seen before include "Aerobatic device" , "High swing" , "Flying bar for acrobatics" , "Swing used by circus acrobats" , "Apparatus for circus acrobats" .)