Character associated with 'The Big Sleep'? Yes and no (3,3,6)
I believe the answer is:
rip van winkle
'no' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'character associated with 'the big sleep'? yes and' is the wordplay.
I cannot really see how this works, but
'character' could be 'rip' (I have seen 'Louche character' mean 'rip' so perhaps 'character' could also mean 'rip') and 'rip' is found in the answer.
'with' could be 'w' (abbreviation) and 'w' is located in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for rip van winkle that I've seen before include "long kipper" , "Person oblivious to social change" , "Someone who sleeps a lot (for 20 years?)" , "Washington Irving hero" , "Twenty-year sleeper (W. Irving)" .)