Started to eat a morsel (3)
I believe the answer is:
bit
'morsel' is the definition.
(synonyms)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for bit that I've seen before include "Morsel" , "Unspoken" , "Small piece; boring tool" , "Small piece - used teeth" , "a curb?" .)