Men overheard in this pretence (5)
I believe the answer is:
guise
'this pretence' is the definition.
('guise' can be a synonym of 'pretence')
'men overheard' is the wordplay.
'men' becomes 'guys'.
'overheard' indicates a 'sounds like' (homophone) clue.
'guys' sounds like 'GUISE'.
'in' is the link.
(Other definitions for guise that I've seen before include "General appearance" , "Demeanour" , "Shape; pretence" , "Semblance; likeness" , "Mask" .)