A funny mood? (6)
I believe the answer is:
humour
'a funny mood?' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for humour that I've seen before include "Temperament; comedy" , "A funny thing" , "A sense of . . . . . . - the quality of enjoying amusing things" , "Gratify by compliance" , "Quality of funniness" .)