Bad mood comes to prominence (4)
I believe the answer is:
hump
'to prominence' is the definition.
(synonyms)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for hump that I've seen before include "Protuberance on back, road etc" , "A dromedary has one" , "sleeping policeman" , "Protuberance; (the) sulks" , "Rounded protuberance" .)