Ate bit - peeled food - on end of fork (7)

'ate' is the definition.
Although both the answer and definition are past participle verbs, I don't see how one could define the other.

'bit peeled food on end of fork' is the wordplay.
'bit' becomes 'part' (both can mean a piece of something).
'peeled' says to take the centre (outer letters are peeled off).
'on' means one lot of letters go next to another.
'end of' says to take the final letters.
The central letters of 'food' are 'oo'.
The final letter of 'fork' is 'k'.
'part'+'oo'+'k'='PARTOOK'

Can you help me to learn more?