Insure \In"sure\, v. t. [imp. & p. p. Insured; p. pr. & vb. n. Insuring.]

[OE. ensuren, prob. for assuren, by a change of prefix. See 1st In-, and Sure, and cf. Assure, Ensure.]

[Written also ensure.]

1. To make sure or secure; as, to insure safety to any one.

2. 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; as, a merchant insures his ship or its cargo, or both, against the dangers of the sea; goods and buildings are insured against fire or water; persons are insured against sickness, accident, or death; and sometimes hazardous debts are insured.

Source: Webster's Revised Unabridged Dictionary (1913)