Singer at front to shake booty (4)
I believe the answer is:
swag
'booty' is the definition.
(I know that booty can be written as swag)
'singer at front to shake' is the wordplay.
'at front' indicates taking the first letters.
'to shake' becomes 'wag' (synonyms).
The initial letter of 'singer' is 's'.
's'+'wag'='SWAG'
(Other definitions for swag that I've seen before include "stuff stolen" , "Loop of drapery" , "Part of a curtain" , "Burglar's booty" , "Burglar's haul" .)