war·rant 
(wôrənt, wŏr-)
(wôrənt, wŏr-)n.
1. An order that serves as authorization, especially:
a. Law A judicial writ authorizing the search or seizure of property, arrest of a person, or the execution of a legal judgment.
b. A voucher authorizing payment or receipt of money.
c. An option to buy stock at a specified price from an issuing company.
2.
a. Justification for an action or a belief; grounds: "The difficulty of predicting the future is no warrant to ignore it" (Brian Hayes).
b. Something that provides assurance or confirmation; a guarantee or proof: "The kind of uncertainties and ambiguities ... which may damage [his] essays ... are often a warrant of authenticity in [his] fiction" (John Edward Hardy).
3. Authorization or certification; sanction, as given by a superior.
4.
a. A warrant officer.
b. A certificate of appointment given to a warrant officer.
tr.v. war·rant·ed, war·rant·ing, war·rants
1. To provide adequate grounds for; justify or require: What could he have done that would warrant such a punishment?
2.
a. To guarantee (a product).
b. To guarantee (a purchaser) indemnification against damage or loss.
3. Law To guarantee clear title to (real property).
[Middle English warant, from Old North French, of Germanic origin; see wer-4 in the Appendix of Indo-European roots.]
war′rant·a·bili·ty n.
warrant·a·ble adj.
warrant·a·bly adv.
warrant·less adj.