assurance

assurance is on the Academic Word List.

Noun

(countable & uncountable) An assurance is a strong promise, usually given when the listener has doubts.
She had been here before and could give assurance that they were on the right course.

Despite assurances from the contractor that everything was going well, we still felt nervous.
(uncountable) Assurance is the feeling of self confidence.
Cocteau in his trademark suit stared with absolute assurance into the camera.