Wow, that's either cool or the worst word choice ever.
"insure": Provide insurance coverage. Arrange for compensation in the event of damage to or loss of (property), or injury to or the death of (someone), in exchange for...: "the car is insured for loss or damage"
"ensure": Make certain that (something) shall occur or be the case.
"Insure" can also take the latter meaning; I think it's an American/British thing. The New Yorker uses "insure" for both meanings, and it trips me up every time.
At first I thought, "Well, but the New Yorker does have a few quirks" - but the analogous search for the NYT shows that they do it too.
I always assumed "insure" for "ensure" was a sign of illiteracy. What's that thing called in psychology where the brain edits out incongruent things and just doesn't see them? I must have been doing that with "insure" for years.
What part of the US are you living in where ensure is not used? As an American living in the US, this would wind me up too! But for all "intensive purposes" some just don't know any better and don't have the "gaul" to "care less."
It is probably one of these things where Americans swung one way and Brits the other. Another example is http://en.wikipedia.org/wiki/Aluminium#Etymology where Americans use the original British spelling and the Brits use the original American spelling!
But insure and ensure mean different things - they can't be interchanged!
"insure": Provide insurance coverage. Arrange for compensation in the event of damage to or loss of (property), or injury to or the death of (someone), in exchange for...: "the car is insured for loss or damage"
"ensure": Make certain that (something) shall occur or be the case.