Lawman's refusal to wait put queen off once (6)
I believe the answer is:
notary
'lawman's' is the definition.
(a notary is a legal official)
'refusal to wait put queen off once' is the wordplay.
I cannot really understand how this works, but
'refusal' could be 'no' and 'no' is found in the answer.
'queen' could be 'r' (abbreviation for regina, e.g. in ER ) and 'r' is found within the answer.
The remaining letters 'tay' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
(Other definitions for notary that I've seen before include "One drawing up legal documents" , "Person authorised to certify legal documents" , "Official authorised to witness signing of documents" , "Person legally authorised to witness signatures" , "Legal officer" .)