Simple past tense and past participle of overbalance.(verb)
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Use "overbalanced" in a sentence
"The destroyer overbalanced and crashed into the ditch."
"Dana was the thorough-going type of man, not overbalanced and erratic, without quirk or quibble of temperament."
"She overbalanced hard into the rim of a fountain with a thump that echoed dully, and then lurched upright again, landing a wild punch on his shoulder."