noun
Physical air or gaseous atmosphere. Also used in scientific and everyday contexts.
部屋の空気が乾燥している。
The air in the room is dry.
山の空気はとてもきれいだ。
The mountain air is very clean.
noun
The social or emotional atmosphere of a place or group. Often used in the phrase 空気を読む (read the room).
See also: 空気を読む
会議の空気が重かった。
The mood of the meeting was heavy.
彼は空気を読むのが下手だ。
He is bad at reading the room.
noun
someone with no presence; someone who doesn't stand out
Colloquial and idiomatic. Refers to a person who is so unnoticeable that they are treated like air. Often used in phrases like 空気のような存在.
彼はクラスで空気みたいな存在だ。
He is like air in the class—nobody notices him.