Dictionary definition · overturn
noun
- the act of upsetting something"he was badly bruised by the upset of his sled at a high speed"
- an improbable and unexpected victory"the biggest upset since David beat Goliath"
verb
- turn from an upright or normal position"The big vase overturned"
- cause to overturn from an upright or normal position"The cat knocked over the flower vase"
- rule against"The Republicans were overruled when the House voted on the bill"
- cause the downfall of; of rulers"The Czar was overthrown"
- cancel officially"He revoked the ban on smoking"
- change radically"E-mail revolutionized communication in academe"
Source: Open English WordNet (CC BY 4.0).