Monarch stops guard yielding (9)
I believe the answer is:
deference
'yielding' is the definition.
(thesaurus)
'monarch stops guard' is the wordplay.
'monarch' becomes 'er' (abbreviation for Elizabeth Regina).
'stops' indicates putting letters inside.
'guard' becomes 'defence' (I am not sure about this - if you are sure you should believe this answer much more).
'er' inserted into 'defence' is 'DEFERENCE'.
Can you help me to learn more?
(Other definitions for deference that I've seen before include "Compliance with another's wishes, polite respect" , "Submission to will of another" , "show respect" , "Respect; submission" , "honour" .)