Bad-tempered taxi driver carrying Queen (6)
I believe the answer is:
crabby
'bad-tempered' is the definition.
('crabby' can be a synonym of 'bad-tempered')
'taxi driver carrying queen' is the wordplay.
'taxi driver' becomes 'cabby' (I've seen this before).
'carrying' is an insertion indicator.
'queen' becomes 'r' (r is abbreviation regina. e.g. in ER ).
'cabby' going around 'r' is 'CRABBY'.
(Other definitions for crabby that I've seen before include "Grumpy like crustacean" , "Sour and cantankerous like common shellfish" , "Temperamental" , "Sour-tempered like common crustacean" , "Bad-tempered, morose" .)