Nickel-head

Thought to be derived from someone who misheard "knucklehead," a nickel-head is someone who's got quite a few screws loose "up there." They aren't the sharpest tools in the shed. Its meaning stems from the fact that a nickel is valued at only five cents, and thus nickel-heads are a step up from their dimwitted cousins, penny-heads.

"I failed my open book quiz."
"You must be a nickel-head."

Nickel-head by sohanasays December 9, 2013

Nuckel Head McSpazatron 

bluntly a person who acts like they are under the age of four...even though they are much much older
(i.e a "kiddager"]

sponge bob movie...
old lady fish thing: A Nuckel Head McSpazatron.?
spongebob no im a goofy goober

Nuckel Head McSpazatron by iLove spongebob.! August 24, 2009

nicked in the head 

someone who has lost the plot. mild case of insanity. does unexplainable things usually when intoxicated

dave: did you see what tom did last nite

joe: i no i cant believe he tried shagging a tin of beans

dave: hes nicked in the head man, he doesnt know what hes doing after a few beers

nicked in the head by yorkshire kiddo April 25, 2011

Two Headed Nickel

A homosexual who also has kids. Usually referring to a male. Works in tandem with the phrase “three dollar bill”.

He is not just a three dollar bill, because he has kids, he’s a two headed nickel.

Two Headed Nickel by Zo Spinelli February 24, 2021

A Head Full Of Nickels 

A phrase used to describe an absentminded or moronic person who can't retain anything.

Connor, man. Do you hear yourself? You definitely have a head full of nickels.

A Head Full Of Nickels by cablenewz December 28, 2020