transitive verb assured -·sured′, assuring -·sur′·ing

1. to make (a person) sure of something; convince
2. to give confidence to; reassure the news assured us
3. to declare to or promise confidently I assure you I'll be there
4. to make (a doubtful thing) certain; guarantee
5. to make safe or secure
6. Chiefly Brit. to insure against loss, esp. of life

Etymology: ME assuren < OFr asseurer < ML assecurare < L ad-, to + securus, secure