One giving a nip holding tip of toe, like crabs? (6)
I believe the answer is:
bitter
'like crabs?' is the definition.
('crabby' can mean 'bitter')
'one giving a nip holding tip of toe' is the wordplay.
'one giving a nip' becomes 'biter'.
'holding' is an insertion indicator.
'tip of' indicates taking the first letters.
The initial letter of 'toe' is 't'.
'biter' going around 't' is 'BITTER'.
(Other definitions for bitter that I've seen before include "Resentful or angry through disappointment" , "Sour like some English beer" , "Sour taste or resentful" , "Resentful and cynical" , "Tart like some English beer" .)