Word

真空

しんくう
vacuum; hollow; empty
Word

防空

ぼうくう
air defense; air defence
Word

天空

てんくう
sky; air; ether; firmament; the heavens
Word

大空

おおぞら
heavens; firmament; sky
Word

空挺

くうてい
airborne
Word

空白

くうはく
blank space; vacuum; space; null (NUL)
Word

空冷

くうれい
air cooling
Word

星空

星ぞら
ほしぞら
starry sky
Word

空想

くうそう
daydream; fantasy; fancy; vision
Word

開く

空く、明く
あく
to open (e.g. doors); to open (e.g. business, etc.); to be empty; to be vacant; to be available; to be free; to be open (e.g. neckline, etc.); to have been opened (of one's eyes, mouth, etc.); to come to an end; to open (one's eyes, mouth, etc.); to have a hole; to form a gap; to have an interval (between events)