Main Entry: en·sure

Pronunciation: \in-ˈshu̇r\

Function: transitive verb

Inflected Form(s): en·sured; en·sur·ing

Etymology: Middle English, from Anglo-French ensurer, alteration of assurer — more at assure

Date: 1660

: to make sure, certain, or safe : guarantee

synonyms ensure, insure, assure, secure mean to make a thing or person sure. ensure, insure, and assure are interchangeable in many contexts where they indicate the making certain or inevitable of an outcome, but ensure may imply a virtual guarantee <the government has ensured the safety of the refugees>, while insure sometimes stresses the taking of necessary measures beforehand <careful planning should insure the success of the party>, and assure distinctively implies the removal of doubt and suspense from a person's mind <I assure you that no harm will be done>. secure implies action taken to guard against attack or loss <sent reinforcements to secure their position>.