Fancy beginning to egg on worker (7)
I believe the answer is:
elegant
'fancy' is the definition.
(thesaurus)
'beginning to egg on worker' is the wordplay.
'beginning to' indicates taking the first letters.
'on' becomes 'leg' (cricket term, fielding positions**).
'worker' becomes 'ant' (worker is a type of ant).
The initial letter of 'egg' is 'e'.
'e'+'leg'+'ant'='ELEGANT'
(Other definitions for elegant that I've seen before include "Chic; smart" , "Stylish in appearance, a gentle kind" , "Modish" , "Tasteful and refined in appearance" , "Gracefully stylish" .)