noun
temporary class closure; school class suspension
Refers to the temporary closure of a school class (not the whole school) due to illness outbreaks, weather, or other emergencies.
インフルエンザで学級閉鎖になった。
The class was closed temporarily due to influenza.
大雪のため、明日は学級閉鎖です。
Due to heavy snow, classes will be closed tomorrow.