To disestablish a church is to pass an official decision that it is no longer the official church of the country. The church can still exist and still hold services; it just loses its special state job — public money, legal privilege, being “the” church of the nation. This is a narrow, historical, legal word. You will meet it in British and Irish history (fights over the Church of England or the Church of Ireland) more than in daily American English, because the United States did not have one national church in the same way. Though actually, students who guess from establish often think it means “close a school” or “shut a company down.” It almost never means that. You disestablish an established church, not a café. There is a famous related noun, disestablishment, and an even more famous joke-word, antidisestablishmentarianism, built on the same idea.

取消某教會的國家官方宗教地位。注意：台灣口中的「國教」是國民教育，不是這個意思。