Crossword Genius

Jumper showing signs of exertion? (7)

Ross

I believe the answer is:

sweater

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

But I can't explain it at all! Could you help me understand?

(Other definitions for sweater that I've seen before include "mugger once" , "One visibly too hot" , "Jumper (7)" , "Long-sleeved pullover" , "Heavy jersey" .)

I've seen this clue in The Mirror.
Want a hint initially instead of a full solution? Install my app