Part of lab of fine researcher (6)
I believe the answer is:
boffin
'researcher' is the definition.
(boffin is a kind of researcher)
'part of lab of fine' is the wordplay.
'part of' says the answer is hidden in the clue.
'BOFFIN' is hidden within 'lab of fine'.
(Other definitions for boffin that I've seen before include "Technical researcher" , "Military scientist" , "Technical expert" , "Brainbox" , "Back-room boy" .)