Accepting, thanks to monarch (6)
I believe the answer is:
taking
'accepting' is the definition.
(taking is a kind of accepting)
'thanks to monarch' is the wordplay.
'thanks' becomes 'ta' (UK informal version of 'thank you').
'to monarch' becomes 'king' (male monarch).
'ta'+'king'='TAKING'
(Other definitions for taking that I've seen before include "Seizing, appropriating" , "infectious" , "Removal" , "acceptance" , "Accepting" .)