Groom's bunch of straw -- or strap, when this? (4)
I believe the answer is:
wisp
'groom's bunch' is the definition.
'wisp' can be an answer for 'bunch' (wisp is a kind of bunch). I am not certain of the 'groom's' bit.
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for wisp that I've seen before include "Small thin bunch/strand (of something)" , "Small tuft of hair" , "Small thin line of cloud or smoke" , "Slight trace" , "Thin girl" .)