This is the 1087th most frequent Japanese word.
空気
Air; atmosphere.
空気 refers to the physical air or atmosphere in a specific place.
教室の空気が新鮮だった。
The air in the classroom was fresh.
空気 metaphorically represents the mood or atmosphere felt in a room.
彼女が来ると、部屋の空気が明るくなった。
When she came, the atmosphere in the room became brighter.
空気 is used metaphorically to describe the social context or situation.