Suffering from a bruising defeat? (6-2)

I believe the answer is:

beaten-up

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

'suffering from a bruising defeat?' is the definition.
Both the definition and answer are adjectives. Perhaps there's a link between them I don't understand?

'defeat?' is the wordplay.
I cannot really see how this works, but
'defeat?' could be 'beat' (synonyms) and 'beat' is found in the answer.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?

I've seen this clue in The Telegraph.

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.