Baker perhaps chasing rodent: something toothy (7)
I believe the answer is:
ratchet
'something toothy' is the definition.
I can't judge whether this defines the answer.
'baker perhaps chasing rodent' is the wordplay.
'baker perhaps' becomes 'Chet' (trumpeter Chet Baker).
'chasing' says to put letters next to each other (some letters chase after others).
'rodent' becomes 'rat' (rat is a kind of rodent).
'chet' after 'rat' is 'RATCHET'.
Can you help me to learn more?
(Other definitions for ratchet that I've seen before include "Bar to fit the notches of a toothed wheel" , "One-way mechanism" , "Device consisting a toothed wheel and pawl that allows movement in one direction only" , "this will stop revolutionary backsliding" , "Device promoting One Direction" .)