dumbest
adj. A2 Elementary US //ˈdəməst// UK //dˈʌməst// dumb·est
adj. the most stupid or least intelligent. You use this to describe the most foolish choice or person in a group.
adj. the superlative form of 'dumb'; indicates the highest degree of stupidity or lack of good judgment.
That was the dumbest mistake I have ever made.
He realized it was the dumbest idea to leave his car unlocked in the middle of the city.
The committee dismissed the proposal as the dumbest possible solution to a problem that required nuanced, long-term strategic thinking.
Usage
Superlative form; typically follows 'the' and precedes a noun or stands alone after a linking verb.