Rupture means to break or burst suddenly, often with force. When a pipe ruptures in your school, water might spray everywhere because the metal split apart under pressure. When a balloon ruptures, it pops with a sudden burst. The word captures that sense of something breaking apart quickly and completely.

Doctors use rupture to describe when something tears or breaks inside the body, like when an athlete ruptures their Achilles tendon (the thick cord connecting your calf muscle to your heel). That injury doesn't happen gradually: the tendon snaps suddenly, sometimes with a popping sound.

The word also describes breaks in relationships or agreements. When two countries rupture diplomatic relations, they cut ties completely and abruptly, ending their formal connection. A ruptured friendship means something broke the relationship so badly that it ended suddenly rather than just fading away.

Rupture works as both a verb (the dam ruptured) and a noun (the rupture in the dam caused flooding). The word always suggests suddenness and completeness: not a crack that might be fixed easily, but a break that changes everything in an instant.