Fumble for words
I believe the answer is:
haw
'fumble for words' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for haw that I've seen before include "Hedge fruit" , "Small red berry of a thorny tree" , "Fruit of the hawthorn" , "Fruit of a thorny bush" , "Berry of a thorny shrub" .)