overturn

verb

• 1tip (something) over so that it is on its side or upside down:the crowd proceeded to overturn cars and set them on fire
• [no object] turn over and come to rest upside down, typically as the result of an accident:a large housetrailer overturned in the middle of the road

• 2abolish, invalidate, or reverse (a previous system, decision, situation, etc.):the results overturned previous findings he fought for eight years to overturn a conviction for armed robbery

noun

• an act of turning over or upsetting something; a revolution, subversion, or reversal.
• Ecology the occasional (typically twice yearly) mixing of the water of a thermally stratified lake.