noun
student strike; school boycott
Refers to a coordinated refusal by students to attend classes, typically as a form of protest. Often used in historical or news contexts.
学生たちは学費値上げに反対して同盟休校を行った。
The students staged a school boycott to protest the tuition hike.
Compound of 同盟 (alliance, union) and 休校 (school closure). The term likely emerged in the context of student movements, where students would collectively refuse to attend classes as a form of protest.