Those in support of trousers? (5)
I believe the answer is:
belts
'trousers?' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Maybe you can see an association between them that I don't see?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for belts that I've seen before include "Waist bands" , "Fat controllers perhaps" , "Hits" , "Leather bands" , "Moves quickly" .)