Derf 

The number between 6 and 7

"Yo what's that number"
"Nigga, it's Derf"

Derf by killingbird September 9, 2016

Derf 

1. When someone accidentally calls you anderf when your name is Andrew and it sticks forever

2. A really fucking dumb and weird boy

1.yo derf

2. That kid is such a derf

Derf by Djalma si December 4, 2017

derf 

a derf, otherwise know as an idiot is used when someone is being stupid (an idiot)

“Quick being a derf, ya derf”

derf by derf14 June 29, 2019

derf 

derf is unit of measure that measures derfs

the equivalent of a derf is one derf

derf by lookandlineage January 1, 2021

Derf 

In mid-Michigan slang, to trip or fall.

I derfed it so hard on the trail this morning!

Derf by Jnnza January 24, 2021

Derf 

Someone who isn't very smart, and gives you the constant urge to want to hit them in the face with a toy Nerf gun when you look at them or when they speak.

Ugh! Ray annoys me everytime I hear him talk! He's such a derf, I swear!

Derf by Hustle_OnFleek December 28, 2022

Derf Smash 

When one of your friends attempts to become the incredible hulk when drunk and no one will give them more alcohol.

Fred went derf smash on the table and broke it after everyone hid the alcohol from his drunk ass.

Derf Smash by Steve_42 January 25, 2009