ensure

The story

1. Old French · derived fromseur“sure”
2. Anglo-Norman · derived fromenseurer
3. Middle English · inherited fromensuren
4. English todayensure

From Middle English ensuren, from Anglo-Norman enseurer, from Old French seur (“sure”). Doublet of insure.

Words from the same roots

First known use, by meaning

• from 18th c. To make sure or certain of something (usually some future event or condition).
• 14th–18th c. To make a pledge to (someone); to promise, guarantee (someone of something); to assure.