Amusing performer depressed in outskirts of Croydon (5)
I believe the answer is:
clown
'amusing performer' is the definition.
(I know this)
'depressed in outskirts of croydon' is the wordplay.
'depressed' becomes 'low' (synonyms).
'in' is an insertion indicator.
'outskirts of' says to hollow out the word (remove centre letters) (only letters on the outskirts).
'croydon' with its centre taken out is 'cn'.
'low' placed inside 'cn' is 'CLOWN'.
(Other definitions for clown that I've seen before include "Long-booted, bow tie-twirling circus entertainer" , "Slapstick entertainer" , "Red-nosed, long-shoed entertainer" , "Jester" , "Foolish chap" .)