English lad clutching new jet (5)
I believe the answer is:
ebony
'jet' is the definition.
(thesaurus)
'english lad clutching new' is the wordplay.
'english' becomes 'e' (abbreviation).
'lad' becomes 'boy' (I've seen this before).
'clutching' is an insertion indicator.
'new' becomes 'n'.
'boy' placed around 'n' is 'bony'.
'e'+'bony'='EBONY'
(Other definitions for ebony that I've seen before include "Black hardwood" , "'Hard, dark wood (5)'" , "Hard wood used for black piano keys and in cabinetwork" , "Dark hardwood" , "hard stuff" .)