from The American Heritage® Dictionary of the English Language, 4th Edition

  • transitive v. To provide or arrange insurance for: a company that insures homeowners and businesses.
  • transitive v. To acquire or have insurance for: insured herself against losses; insured his car for theft.
  • transitive v. To make sure, certain, or secure. See Usage Note at assure.
  • intransitive v. To buy or sell insurance.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • v. To provide for compensation if some specified risk occurs. Often agreed by policy (contract) to offer financial compensation in case of an accident, theft or other undesirable event.
  • v. To deal in such contracts; subscribe to a policy of insurance
  • v. Alternative spelling of ensure: (transitive) To make sure or certain of; guarantee.
  • v. Alternative form of assure: (transitive) To give confidence in the trustworthiness of.

from the GNU version of the Collaborative International Dictionary of English

  • intransitive v. To underwrite; to make insurance.
  • transitive v. To make sure or secure.
  • transitive v. Specifically, to secure against a loss by a contingent event, on certain stipulated conditions, or at a given rate or premium; to give or to take an insurance on or for

from The Century Dictionary and Cyclopedia

  • To make sure, certain, or secure; give assurance of; assure: as, to insure safety to any one.
  • Specifically To guarantee or secure indemnity for future loss or damage (as to a building from fire, or to a person from accident or death) on certain stipulated conditions; make a subject of insurance; assure: as, to insure a ship or its cargo, or both, against the dangers of the sea; to insure a house against fire.
  • To pledge; betroth.
  • Synonyms Insure, Assure. Assure may express the making certain in mind: as, I was assured of safety by his friendly manner; insure has not this sense. Insure is a possible word to express the making certain in fact, and is more common than ensure: as, his lack of money insured his early return; assure has not this sense. Insure and assure are both used of the act of pledging a payment of money upon loss or death, but assure is rarely used in that sense in the United States.
  • To undertake to secure or assure against loss or damage on receipt of a certain payment or premium; make insurance: as, the company insures at a low premium.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • v. protect by insurance
  • v. make certain of
  • v. take out insurance for
  • v. be careful or certain to do something; make certain of something


Middle English ensuren, to assure, from Old French enseurer, possibly variant of assurer; see assure.
(American Heritage® Dictionary of the English Language, Fourth Edition)
Recorded since c.1440, as a variant of Middle English ensuren (from Anglo-Norman enseurer, itself from en- "make" + Old French seür "sure", probably influenced by Old French asseürer "to assure"); took on its particular sense of "make safe against loss by payment of premiums" in 1635, replacing assure. (Wiktionary)


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