i Register
In some senses, assure is marked as obsolete. Watch for register when choosing this word.
verb
To make sure and secure; ensure.
To give (someone) confidence in the trustworthiness of (something).
I assure you that the program will work smoothly when we demonstrate it to the client.
He assured of his commitment to her happiness.
To guarantee, promise (to do something).
That as a law for euer should endure; / Which to obserue in word of knights they did assure.
To reassure.