To be or prove false to. To play false to (a person); to betray, deceive. Also absol.

To be or prove false to, play false, deal treacherously with; to betray. Obsolete.

To swear (something) falsely; to break (an oath); to forsake (sworn allegiance).

transitive. To prove false to (a person) to whom one has sworn an oath. Obsolete. rare.

gen. To deceive, cheat, trick, delude (obsolete); to cheat (one's) expectation; to prove false or faithless to (any one): to ‘throw over’ or discard…