Get off with airhead blonde (6)
I believe the answer is:
alight
'get off' is the definition.
'with airhead blonde' is the wordplay.
'with' means one lot of letters go next to another.
'airhead' becomes 'a' (head letter of 'air').
'blonde' becomes 'light' (I've seen this before).
'a'+'light' is 'ALIGHT'.
(Other definitions for alight that I've seen before include "Come down - on fire" , "Descend, being on fire" , "Settle; on fire" , "Touch down" , "Step off the bus because it's on fire?" .)