A cross monarch develops appetite to expel party leader and so he goes to live elsewhere (10)
I believe the answer is:
expatriate
'a cross monarch develops appetite to expel party leader and so he goes to live elsewhere' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'cross monarch develops appetite to expel party leader and so he goes to live elsewhere' is the wordplay.
I cannot really understand how this works, but
'cross' could be 'x' (X is cross-shaped) and 'x' is found within the answer.
'monarch' could be 'r' (abbreviation for regina, e.g. in ER ) and 'r' is present in the answer.
'leader' could be 'e' (I've seen this in other clues) and 'e' is found in the answer.
'he' could be 'pat' (I've seen this before) and 'pat' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for expatriate that I've seen before include "foreigner?" , "one based abroad?" , "Brit abroad?" , "resident abroad" , "in exile" .)