Patronising hot and bothered author in hotel (6-4-4)
I believe the answer is:
holier-than-thou
'patronising' is the definition.
'hot and bothered author in hotel' is the wordplay.
'hot' becomes 'h' (abbreviation eg on taps).
'and' means one lot of letters go next to another.
'bothered' indicates an anagram.
'author'+'in'+'hotel'='authorinhotel'
'authorinhotel' with letters rearranged gives 'olierthanthou'.
'h'+'olierthanthou'='HOLIER-THAN-THOU'
(Other definitions for holier-than-thou that I've seen before include "Self-righteous" , "Sanctimonious" .)