Dictionary entry

Invalidate

Webster's Dictionary 1913

In‐val″i‐date (?), v. t. [imp. & p. p.Invalidated (?); p. pr. & vb. n.Invalidating.] [From Invalid null.] To render invalid; to weaken or lessen the force of; to destroy the authority of; to render of no force or effect; to overthrow; as, to invalidate an agreement or argument.