Webster's Revised Unabridged Dictionary · 1913

Assure

Assure ({not transcribed}) , transitive verb

[Old French aseurer, French assurer, Late Latin assecurare; Latin ad + securus secure, sure, certain. See Secure, Sure, and compare Insure.]

1.
To make sure or certain; to render confident by a promise, declaration, or other evidence.
His promise that thy seed shall bruise our foe... Assures me that the bitterness of death Is past, and we shall live. — Milton
2.
To declare to, solemnly; to assert to (any one) with the design of inspiring belief or confidence.
I dare assure thee that no enemy Shall ever take alive the noble Brutus. — Shakespeare
3.
To confirm; to make certain or secure.
And it shall be assured to him. — Lev. xxvii. 19
And hereby we know that we are of the truth, and shall assure our hearts before him. — 1 John iii. 19
4.
To affiance; to betroth. [Obsolete] — Shakespeare
5.
(Law) To insure; to covenant to indemnify for loss, or to pay a specified sum at death. See Insure.