A boxer normally has one even if not hungry (6,7)

I believe the answer is:

second helping

I'm a little stuck... Click here to teach me more about this clue!

'a boxer normally' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'one even if not hungry' is the wordplay.
I cannot really understand how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found in the answer.
'not' could be 'con' (I've seen this in other clues) and 'con' is located in the answer.
This explanation may well be incorrect...

'has' is the link.

Can you help me to learn more?

I've seen this clue in The Globe and Mail.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.