reviver
This is usually "a person who revives something or someone." The palindrome is "reviver."
REVIVER
A palindrome for a slang term for a dumb person could be "dim mid."
boob
boob
boob
refer
gag (if you put it in the mouth to silence a person) pop (like 'to pop some candy into your mouth')
boob
gig
Solos
solos