insure

American Heritage® Dictionary of the English Language, Fourth Edition

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

Century Dictionary and Cyclopedia

1. To make sure, certain, or secure; give assurance of; assure: as, to insure safety to any one.
2. 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.
3. To pledge; betroth.
4. 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.
5. 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.

Wiktionary

1. v. transitive 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.
2. v. intransitive To deal in such contracts; subscribe to a policy of insurance
3. v. alternative spelling of ensure: (transitive) To make sure or certain of; guarantee.
4. v. perhaps nonstandard Alternative form of assure: (transitive) To give confidence in the trustworthiness of.

GNU Webster's 1913

1. v. To make sure or secure.
2. 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
3. v. To underwrite; to make insurance.

WordNet 3.0

1. v. protect by insurance
2. v. make certain of
3. v. take out insurance for
4. v. be careful or certain to do something; make certain of something