Fleshy part of carrot underground (6)
I believe the answer is:
rotund
'fleshy' is the definition.
(thesaurus)
'part of carrot underground' is the wordplay.
'part of' indicates a hidden word.
'ROTUND' can be found hidden inside 'carrot underground'.
(Other definitions for rotund that I've seen before include "Bulging" , "Chubby" , "Rather obese" , "Pleasantly plump or rounded" , "Portly" .)