[ uhn-sel ]
/ ʌnˈsɛl /

verb (used with object), un·sold, un·sell·ing.

to dissuade from a belief in the desirability, value, wisdom, or truth of something: He tried to unsell the public on its faith in rearmament.

Origin of unsell

First recorded in 1925–30; un-2 + sell1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020