If something is compulsory, you must do it or accept it, because it is the law or because someone in a position of authority says you must.
例句
In East Germany learning Russian was compulsory...在东德,俄语是必修课。Many young men are trying to get away from compulsory military conscription.很多年轻人试图逃避强制征兵的政策。
英英词典释义
Adverb
1. in a manner that cannot be evaded;
"the ministry considers that contributions to such a fund should be met from voluntary donations rather than from rates compulsorily levied."