Not entirely hard wood (3)
I believe the answer is:
fir
'wood' is the definition.
(I know that fir is a type of wood)
'not entirely hard' is the wordplay.
'not entirely' means to remove the last letter (most but not all of the word).
'hard' becomes 'firm' (similar in meaning).
'firm' with its last letter taken off is 'FIR'.
(Other definitions for fir that I've seen before include "Pine tree for Gaelic men?" , "Tree with cones" , "Tree for an Irishman" , "Conifer tree" , "wood" .)