noun
militarist
Refers to a person who advocates or supports militarism, often in a political or ideological context.
彼は軍国主義者として知られている。
He is known as a militarist.
Refers to militarism as an ideology or system, while 軍国主義者 refers to a person who supports it.
Compound of 軍国 (military nation) + 主義 (doctrine, -ism) + 者 (person). The term is a straightforward Sino-Japanese formation.