economic independence; self-sufficiency; autarky
Refers to the state of being financially independent, not relying on others for economic support. Can be used for individuals, households, or nations. 'Autarky' is a technical economic term for national self-sufficiency.
若者の経済的自立を支援する政策が求められている。
Policies to support the economic independence of young people are needed.
彼女は経済的自立を目指
She obtained qualifications aiming for economic self-sufficiency.
経済的自立 is the general term for financial independence, while ＦＩＲＥ specifically names the movement combining that independence with early retirement.
Compound of 経済的 (economic) + 自立 (independence). The term is a straightforward modern coinage reflecting the concept of financial autonomy.