One biting into others partly (5)
I believe the answer is:
tooth
'one' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'biting into others partly' is the wordplay.
'partly' indicates a hidden word (part of the clue is used).
'TOOTH' is hidden within 'biting into others'.
Can you help me to learn more?
(Other definitions for tooth that I've seen before include "Taste" , "Biter" , "for drilling and extraction" , "Fang; cog" , "Canine, for example" .)