to destroy the power of; overthrow; defeat; vanquish.
to turn over on its side, face, or back; upset: to overturn a vase.
to turn on its side, face, or back; capsize: The boat overturned during the storm.
the act of overturning.
the state of being overturned.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.