Passed something in joint? (4)
I believe the answer is:
weed
'passed' is the definition.
(weeing is a kind of passing)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for weed that I've seen before include "Uncultivated plant" , "Unwanted plant - cannabis" , "nuisance in bed" , "gardening" , "Marijuana (slang)" .)