defeat transitive verb [imperfect or past participle Defeated; present participle or verbal noun Defeating.] [From F. défait, OF. desfait, p. p. ofe défaire, OF. desfaire, to undo; L. dis- + facere to do. See Feat, Fact, and cf. Disfashion.]

1. To undo; to disfigure; to destroy. [Obs.]

His unkindness may defeat my life. Shak.

2. To render null and void, as a title; to frustrate, as hope; to deprive, as of an estate.

He finds himself naturally to dread a superior Being that can defeat all his designs, and disappoint all his hopes. Tillotson.

The escheators . . . defeated the right heir of his succession. Hallam.

In one instance he defeated his own purpose. A. W. Ward.

3. To overcome or vanquish, as an army; to check, disperse, or ruin by victory; to overthrow.

4. To resist with success; as, to defeat an assault.

Sharp reasons to defeat the law. Shak.

Syn. – To baffle; disappoint; frustrate.