verb (used with object), en·sured, en·sur·ing.
- to secure or guarantee: This letter will ensure you a hearing.
- to make sure or certain: measures to ensure the success of an undertaking.
- to make secure or safe, as from harm.
- insure(defs 1–3).
verb (tr)
- (may take a clause as object) to make certain or sure; guaranteethis victory will ensure his happiness
- to make safe or secure; protect
late 14c., from Anglo-French enseurer, from en- “make” (see en- (1)) + Old French seur “sure” (see sure); probably influenced by Old French asseurer “assure.” Related: Ensured; ensures; ensuring.