ちゃくせき着席chakuseki
1.

The act of positioning oneself in a designated seat, often in a formal setting such as a meeting or performance.

2.

The process of arranging oneself in a sitting position on a chair or similar furniture, typically indicating the beginning of an event or activity.

3.

The action of occupying a seat, signaling readiness or participation in a gathering or event.

4.

The transition from standing or moving to being seated, often accompanied by a formal request or instruction to take one's place.

Example:

どうぞご着席ください、みなさん。