To assert the truth of.To confirm; verify; prove to be true.To affirm with confidence; declare in a positive or peremptory manner.In law, to avouch or verify; offer to verify; allege as a fact.To assert the existence of; offer in evidence.Synonyms Affirm, Declare, etc. (see assert), say, allege, protest, insist, maintain.n. Substance; property; estate.n. plural Live stock; cattle; domestic animals.—n. A beast of burden; a draft-ox or draft-horse; an old horse.