Band that breaks up? (5)
I believe the answer is:
strap
'band' is the definition.
(both can mean a strip of material)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for strap that I've seen before include "Fasten; punishment" , "Tie" , "Leather thong" , "Shoulder band" , "something to hang on to" .)