stoner-brain 

1. Person
a)who is habitually intoxicated by drugs and/or alcohol
b)who is unable to think clearly and make sound decisions due to habitual use of narcotics.
2. Refers to the impaired mental ability of a drug addict to make rational and consistent thoughts

Tom is a stoner-brain so high on bong he can't tell his dick from his ass

stoner-brain by WebC December 3, 2007

Stoner's Brain Syndrome 

When a stoner, particularly someone who smokes marijuana a lot or used to, can't remember what is being conversed about. They instantly forget many things.

"so i kissed him."
"really? when?"
"yesterday."
"did you kiss him?"
"..yes?"

"sorry. i have stoner's brain syndrome.

Stoner's Brain Syndrome by kpillow. August 21, 2010

Brain of stone 

To be Indecisive.

Or unlikeable; selfish.

" Is that Vanessa? I heard she has a Brain of stone!" I heard too.

Brain of stone by hollowlungs October 27, 2022

Stonebrain 

A term used to denote one's stupidity; mentally handicapped by the amount of pebbles and sediment in their cranium.

Guy 1: I've really gotten into THING I DISAGREE WITH.
Guy 2: LOOOOOOOOLLLL shut the fuck up, you stonebrain-ass bitch. How much sediment you got up there, huh? I can see pebbles coming out of your ears, bro.

Stonebrain by GimmickConnections February 14, 2021