Spaced out, also very arrogant (4,3,6)
I believe the answer is:
high and mighty
'arrogant' is the definition.
(I've seen this before)
'spaced out also very' is the wordplay.
'spaced out' becomes 'high' (both can mean on drugs).
'also' becomes 'and' (I've seen this in another clue).
'very' becomes 'mighty' (synonyms).
'high'+'and'+'mighty'='HIGH-AND-MIGHTY'
(Other definitions for high and mighty that I've seen before include "Arrogant - pompous" , "Acting as if one believes one is very important" , "Self-important" , "Stuck up" , "like the Sun, perhaps? - with 9a,10a" .)