KSI

A big Fatneek. A person who loves to lose weight even though it doesn't work.

My brother's a real KSI, he doesn't give up.

by dutchdorm September 17, 2021

KSI

A cool London rapper / Boxer / Youtuber who likes spending money on things like 500k anime necklaces and 200k watches just for tax returns

He also beated Logan Paul twice, what an absolute unit

KSI demolished that silly boy logan paul

by Jon does sugar November 10, 2019

ksi

small man with a big forehead

Hey look there's ksi he's a small man with a big forehead

by shushbequiet April 9, 2021

Ksi

Just a big fatneek

Ksi is a FATNEEK.

by Tayem is a shitbox lover November 22, 2021

KSI

KSI is a clan in Halo

KSI now means Knowledge, Strength and Integrity

Make up your mind JJ

“Yo Fitz lets play Halo, I heard KSI is giving some rewards!”

by Holy!oly August 12, 2019

KSI

An african youtuber/boxer/rapper orginated from England, Watford. But claims himself as a nigerian.
K="knowledge"
S="strength"
I= Intergrity
Famous quotes
Allow it fam, gangshit, for fuck sake man, you guys are pricks, shut up, kilode, akneehow, etc
Other Names:
Follabi, Babatunde, Sir Theodore the 3rd, fatneek

KSI: Ah ah, kilode, its nice to see you ah!
Tobi: Ah ah, my nigerian brother ksi!
____________
Harry: KSI is a fatneek

by The Aquarium Lad December 14, 2020

KSI

KSI is an animal with a BIG BIG forehead and a FATNEEK with a crappy beard.

KSI is a fatneek

by KSIhaveAbigFOREHEAD June 29, 2021