To answer your question accurately, I need to know the specific words you're referring to. Please provide the list of words, and I'll help you determine which one doesn't fit.
stop or halt is a four letter word meaning the opposite of go.
if I remember correctly, the root word for 4 is quad or quart...
A four letter word for 'don't go' is stay.
stop
over
Seek
swim?
dawn
The 8-letter word that contains four 'N's and the other four letters are all vowels is "announcer."
to look or to seek
that would be "seek"
posthaste