Sinks one’s teeth into (5)
I believe the answer is:
bites
'sinks one's teeth into' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bites that I've seen before include "Breaks with the teeth" , "Nibbles" , "Stings" , "Nips to" , "Morsels" .)