Gracious and firm queen (3)
I believe the answer is:
cor
'gracious' is the definition.
(both are exclamations of surprise)
'firm queen' is the wordplay.
'firm' becomes 'co' (a firm is a company).
'queen' becomes 'r' (abbreviation for regina, e.g. in ER ).
'co'+'r'='COR'
'and' acts as a link.
(Other definitions for cor that I've seen before include "Gosh" , "Surprised expression" , "Expression of surprise" , "Blimey" .)