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.”