Passed out in black suits (6)
I believe the answer is:
spades
'black suits' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps you can see an association between them that I can't see?
'passed out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'passed' with letters rearranged gives 'SPADES'.
'in' is the link.
Can you help me to learn more?
(Other definitions for spades that I've seen before include "Digging implements" , "Garden tools and card suit" , "Passed around with diggers" , "dark suit" , "Suit in pack of cards" .)