空【から】
emptiness, being empty, not carrying anything, unburdened, empty-handed, dishonoured (bill, promise, etc.), false, no-show (reservation), put-on (cheeriness, courage, etc.), empty (compliments), insincere
空気【くうき】
air, atmosphere, mood, situation, someone with no presence, someone who doesn't stand out at all
空【そら】
sky, the air, the heavens, weather, far-off place, distant place, state of mind, feeling, (from) memory, (by) heart, falsehood, lie, somehow, vaguely, fake
空【くう】
empty air, sky, shunyata (the lack of an immutable intrinsic nature within any phenomenon), emptiness, air force, fruitlessness, meaninglessness, void (one of the five elements), empty (e.g. set)
空港【くうこう】
airport
空間【くうかん】
space, room, airspace
空く【すく】
to become less crowded, to thin out, to get empty, to be hungry
航空機【こうくうき】
aircraft
空爆【くうばく】
aerial bombing
空白【くうはく】
blank space (in documents), vacuum, blank, void
架空【かくう】
fictitious, imaginary, fanciful, fabricated, aerial, overhead
空襲【くうしゅう】
air-raid
空洞【くうどう】
cave, hollow, cavity, hollow
青空【あおぞら】
blue sky
空母【くうぼ】
aircraft carrier
空席【くうせき】
empty seat, unoccupied seat, vacancy, vacant post
空前【くうぜん】
unprecedented, record-breaking
航空自衛隊【こうくうじえいたい】
Japan Air Self-Defense Force, JASDF
空域【くういき】
airspace
空き缶【あきかん】
empty can
