Weird, just one of red, green, blue or black in snooker game? (7)
I believe the answer is:
oddball
'weird' is the definition.
(I've seen this in another clue)
'one of red green blue or black in snooker game?' is the wordplay.
I cannot really see how this works, but
'one' could be 'odd' (I've seen this before) and 'odd' is present in the answer.
'black' could be 'b' (as in pencil classifications) and 'b' is found within the answer.
The remaining letters 'all' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'just' is the link.
(Other definitions for oddball that I've seen before include "Weird" , "case" , "eccentric type" , "Eccentric person (colloq.)" , "Eccentric character" .)