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. 
"hey ill be right back i gotta go have a choom with my buddies"
"i caught Jim chooming last night, what a weirdo"
"im all worn out from that choom"
"i caught Jim chooming last night, what a weirdo"
"im all worn out from that choom"
by 5nizza April 5, 2021
Get the choommug.