A 6-letter word meaning stupidity is "foolish." It describes a lack of good sense or judgment, often associated with making unwise decisions. This term is commonly used to convey a sense of silliness or imprudence.
Winner is a 6 letter word with a meaning to win a victory over.
Safety... "Safety" is a 6 letter word
unison
Retain.
impish
purify
united
confused
agenda
leader
The word is likely "modern."
The word is "retard."