Doom ruined tantrum (4)
I believe the answer is:
mood
'tantrum' is the definition.
The answer and definition can be both states of affairs as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'doom ruined' is the wordplay.
'ruined' is an anagram indicator.
'doom' anagrammed gives 'MOOD'.
Can you help me to learn more?
(Other definitions for mood that I've seen before include "Humour - bad temper" , "Frame of mind" , "feelings" , "melancholy" , "Temporary state of mind" .)