From WordNet (r) 2.0 (August 2003) [wn]:
insure
v 1: be careful or certain to do something; make certain of
something; "He verified that the valves were closed";
"See that the curtains are closed"; "control the quality
of the product" [syn: see, check, see to it,
ensure, control, ascertain, assure]
2: make certain of; "This nest egg will ensure a nice
retirement for us"; "Preparation will guarantee success!"
[syn: guarantee, ensure, assure, secure]
3: protect by insurance; "The insurance won't cover this" [syn:
cover, underwrite]
4: take out insurance for
From The Collaborative International Dictionary of English v.0.48 [gcide]:
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.]
[1913 Webster]
1. To make sure or secure; as, to insure safety to any one.
[1913 Webster]
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.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Insure \In*sure"\, v. i.
To underwrite; to make insurance; as, a company insures at
three per cent.
[1913 Webster]