Deal with uncle trimming papa's beard (3)
I believe the answer is:
awn
'beard' is the definition.
(both can mean a growth on plants)
'deal with uncle trimming papa's' is the wordplay.
I cannot really see how this works, but
'with' could be 'w' (short for with) and 'w' is found within the answer.
The remaining letters 'an' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for awn that I've seen before include "Bristly head of barley sheath, quite wan" , "Bristly growth" , "Grass "beard"" , "Bristle growing on barley" , "Bristle on grass spikelet" .)