Picked up two words to do with roulette, which I detest (4,5)
I believe the answer is:
bete noire
'roulette which i detest' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'picked up two words to do with' is the wordplay.
I cannot really understand how this works, but
'to do with' could be 're' (regarding) and 're' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for bete noire that I've seen before include "Particular object of loathing" , "Particular dislike" , "One particularly disliked" , "undesirable" , "One's particular bugbear" .)