Chum’s pants (4)
I believe the answer is:
tosh
This might be a double definition.
'chum's' is the first definition.
(I've seen this before)
'pants' is the second definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
Can you help me to learn more?
(Other definitions for tosh that I've seen before include "moonshine" , "Slang nonsense" , "[BLAH]" , "Baloney, twaddle" , "Nonsense; shot (anag.)" .)