空

Proverb; Orig. 男心と秋の空

a woman's heart is as fickle as autumn weather

air superiority

air-to-air missile

open-air classes

castle in the air

spatial awareness; spatial perception

Military

air defense identification zone; ADIZ

Organization name

National Aeronautics and Space Administration (USA); NASA

space manipulation (e.g. supernatural ability)

Organization name

Japan Aerospace Exploration Agency; JAXA

air strike

aerial show; air show; airshow

anti-aircraft fire; shooting at an aircraft (from ground or ship)

aviation fuel

unmanned aerial vehicle (UAV); drone

to play dumb; to feign innocence

Idiomatic expression

to become free; to get time off

Professional wrestling

karate chop

to speak from memory

low-cost carrier; LCC; low-cost airline

Colloquial

flat broke; stone broke; penniless

idle time; down time; window period

army aviation

Buddhism

Akasagarbha (bodhisattva)