One bites firm end of fig (3)
I believe the answer is:
cog
'one bites firm end of fig' is the definition.
I can't judge whether this definition defines the answer.
'firm end of fig' is the wordplay.
'firm' becomes 'co' (a firm is a company).
'end of' indicates one should take the final letters.
The last letter of 'fig' is 'g'.
'co'+'g'='COG'
Can you help me to learn more?
(Other definitions for cog that I've seen before include "minor employee" , "Tooth on the rim of gear wheel" , "Machine wheel" , "Minor player" , "bar" .)