Loyalist

n. person who is loyal to the present government

In general, a loyalist is an individual who is loyal to the "powers that be" or  the establishment, and wishes to retain the status quo. This article specifically refers to individuals and groups who are loyal to the British monarchy and/or to the United Kingdom.
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Noun
1. a person who is loyal to their allegiance (especially in times of revolt)
(synonym) stalwart
(hypernym) supporter, protagonist, champion, admirer, booster, friend

n. loyalist, person loyal to the present government

(n.)
A person who adheres to his sovereign or to the lawful authority; especially, one who maintains his allegiance to his prince or government, and defends his cause in times of revolt or revolution.