Plumlike fruit (6)
I believe the answer is:
damson
'plumlike fruit' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for damson that I've seen before include "Acid purple plum" , "Stone fruit for nomads" , "Plum-coloured" , "Small plum-like fruit" , "Small fruit for nomads" .)