Gradually got teeth into Times piece (3,2,3)
I believe the answer is:
bit by bit
'gradually' is the definition.
(synonyms)
'got teeth into times piece' is the wordplay.
'got teeth into' becomes 'bit' (bit with teeth).
'times' becomes 'by' (both can mean 'multiplied by').
'piece' becomes 'bit' (synonyms).
'bit'+'by'+'bit'='BIT-BY-BIT'
(Other definitions for bit by bit that I've seen before include "in a gradual sequence" , "Piecemeal" , "Gradually, a little at a time" , "Two adjacent pieces" , "What might be found in tack room" .)