To get high. It seems (to me) that the word probably derives from the Spanish verb "chumar," which can refer to intoxication by everything from alcohol to hallucinogens, and which derives from "achuma," the mescaline-containing San Pedro cactus native to the high, dry areas of South America. Conjugation: chumo, chumas, chuma, chumamos, chumaís, chuman. "Estoy chumando duro" = "I'm tripping hard."
A self-selected group of boys (including Barack Obama) at Punahou School who loved basketball and good times called themselves the Choom Gang. Choom is a verb, meaning “to smoke marijuana.”
by Hypodermic Noodle February 10, 2014
Get the choommug. by Nuttin str8 Katrine December 9, 2008
Get the choommug. "Drinking that bottle of ipecac was a bad idea, now I'm gonna CHOOM!"
"I told you not to eat that! Now you got choom all over evrything!"
"I told you not to eat that! Now you got choom all over evrything!"
by Silvar February 4, 2009
Get the choommug. 
Alternative spelling of tume, i.e. tumourous: resembling tumours (unwanted, typically cancerous growths of tissue). Used to describe unpleasant/undesirable phenomenon. The words choomah (tumour) and choomourous (tumourous) can also be used to similar effect.
Spelling is associated the Choomah monsters found on Choomah Island, as featured on Australian cartoon comedy series The Big Lez Show.
Spelling is associated the Choomah monsters found on Choomah Island, as featured on Australian cartoon comedy series The Big Lez Show.
Ethan: Ever since I slept with those two prostitutes I've been getting huge genital warts on my ballsack.
Andy: That's absolutely choom.
Nick: Bro that's bare choomourous, you should get that checked before Kayo finds out.
Andy: That's absolutely choom.
Nick: Bro that's bare choomourous, you should get that checked before Kayo finds out.
by Big Boy 1488 September 24, 2020
Get the choommug.