・ 音 チツ 🔊
Sino-Vietnamese: trất
A hole 穴 reached 至 to its very end: blocked and airless, as in suffocation.
Stroke data: KanjiVG (CC BY-SA 3.0) — kanjivg.tagaini.net
空気の多くは窒素だ。 (くうきのおおくはちっそだ)
Most of the air is nitrogen.