- 1arrange for compensation in the event of damage to or loss of (property), or injury to or the death of (someone), in exchange for regular advance payments to a company or government agency:the table should be insured for $2,500 the company had insured itself against a fall of the dollar [no object]:businesses can insure against exchange rate fluctuations
late Middle English (in the sense 'assure someone of something'): alteration of ensure
There is considerable overlap between the meaning and use of insure and ensure. In both US and British English, the primary meaning of insure is the commercial sense of providing financial compensation in the event of damage to property; ensure is not used at all in this sense. For the more general senses, ensure is more likely to be used, but insure and ensure are often interchangeable, particularly in US English: bail is posted to insure that the defendant appears for trial the system is run to ensure that a good quality of service is maintained.