Audibly makes fun of the appearance (5)
I believe the answer is:
'appearance' is the definition.
(guise is a kind of appearance)
'audibly makes fun of' is the wordplay.
'audibly' indicates a 'sounds like' (homophone) clue.
'makes fun of' becomes 'guys' (guy can mean to tease or mock).
'guys' sounds like 'GUISE'.
'the' is the link.
(Other definitions for guise that I've seen before include "General appearance" , "Appearance, semblance" , "Mask" , "Semblance; likeness" , "Show" .)