Fly as part of jet set's entourage (6)
I believe the answer is:
tsetse
'fly' is the definition.
(tsetse is a kind of fly)
'part of jet set's entourage' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'TSETSE' is hidden in the letters of 'jet sets entourage'.
'as' is the link.
(Other definitions for tsetse that I've seen before include "cause of sleepiness?" , "fly across Africa" , "bloodsucker" , "source of sleeping sickness" , "Bloodsucking African fly" .)