The Collaborative International Dictionary
Annexationist
Annexationist \An`nex*a"tion*ist\, n. One who favors annexation.
Wiktionary
annexationist
n. An advocate of annexation
Usage examples of "annexationist".
On the other hand, a new German offensive would convince the masses of Western Europe that the Bolsheviks only agreed to an annexationist peace under compulsion.