The appearance of chaps, we hear
I believe the answer is:
guise
'the appearance' is the definition.
(guise is a kind of appearance)
'chaps we hear' is the wordplay.
'chaps' becomes 'guys' (both can mean men).
'we hear' shows a homophone (sound like).
'guys' sounds like 'GUISE'.
'of' acts as a link.
(Other definitions for guise that I've seen before include "Show" , "Shape; pretence" , "General appearance" , "Semblance; likeness" , "Appearance, semblance" .)