Cat on rebound lost its head (5)
I believe the answer is:
ounce
'cat' is the definition.
(ounce is a kind of cat)
'on rebound lost its head' is the wordplay.
I cannot quite understand how this works, but
'on' could be 'o' (I've seen this in other clues) and 'o' is located in the answer.
The remaining letters 'unce' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ounce that I've seen before include "Lightweight" , "One-sixteenth of pound" , "one of sixteen in a pound" , "prowler" , "Fraction of a pound" .)