1.To make secure; to give assurance against harm; to guarantee safety to; to give authority or power to do, or forbear to do, anything by which the person authorized is secured, or saved harmless, from any loss or damage by his action. "That show I first my body to warrant." "I'll warrant him from drowning." "In a place Less warranted than this, or less secure, I can not be."
2.To support by authority or proof; to justify; to maintain; to sanction; as, reason warrants it. "True fortitude is seen in great exploits, That justice warrants, and that wisdom guides." "How little while it is since he went forth out of his study, chewing a Hebrew text of Scripture in his mouth, I warrant."
3.To give a warrant or warranty to; to assure as if by giving a warrant to. "(My neck is) as smooth as silk, I warrant ye."