... or another light-headed idiot (4)
I believe the answer is:
lass
'or another' is the definition.
I can't judge whether this definition defines the answer.
'light-headed idiot' is the wordplay.
'light-headed' becomes 'l' (this could be a standard abbreviation which I don't know about).
'idiot' becomes 'ass' (I've seen this in another clue).
'l'+'ass'='LASS'
Can you help me to learn more?
(Other definitions for lass that I've seen before include "Miss" , "Girl (of Richmond Hill?)" , "Damsel" , "Young woman, girl" , "Scottish girl" .)