war·rant (wôr'ənt, wŏr'-)
n.

1. Authorization or certification; sanction, as given by a superior.
2. Justification for an action or a belief; grounds: "He almost gives his failings as a warrant for his greatness" (Garry Wills).
3. Something that provides assurance or confirmation; a guarantee or proof: a warrant of authenticity; a warrant for success.
4. An order that serves as authorization, especially:
   1. A voucher authorizing payment or receipt of money.
   2. Law. A judicial writ authorizing an officer to make a search, seizure, or arrest or to execute a judgment.
5. 1. A warrant officer.
   2. A certificate of appointment given to a warrant officer.

tr.v., -rant·ed, -rant·ing, -rants.

1. To guarantee or attest to the quality, accuracy, or condition of.
2. To guarantee or attest to the character or reliability of; vouch for.
3. 1. To guarantee (a product).
   2. To guarantee (a purchaser) indemnification against damage or loss.
4. To guarantee the immunity or security of.
5. To provide adequate grounds for; justify. See synonyms at justify.
6. To grant authorization or sanction to (someone); authorize or empower.
7. Law. To guarantee clear title to (real property).

[Middle English warant, from Old North French, of Germanic origin.]

warrantability war'rant·a·bil'i·ty or war'rant·a·ble·ness n.
warrantable war'rant·a·ble adj.
warrantably war'rant·a·bly adv.
warrantless war'rant·less adj.

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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

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