evaporation; the physical process in which a liquid becomes vapor.
水を温めると蒸発して水蒸気になる。
When you heat water it evaporates and becomes steam.
フライパンに入れた汁が蒸発して量が減った。
The sauce in the frying pan evaporated and its volume decreased.
蒸発速度は温度と表面積に依存する。
The evaporation rate depends on temperature and surface area.
colloquial: to disappear suddenly or vanish without a trace (often said of a person).
昨日から彼が会社に来ない。まるで蒸発したみたいだ。
He hasn't come to work since yesterday. It's as if he vanished.
借金をしていた友人が蒸発して連絡が取れない。
A friend who owed money disappeared and can't be contacted.