CHUM

n. & v. --n. colloq. (esp. among schoolchildren) a close friend. --v.intr. (often foll. by with) share rooms. øchum up (often foll. by with) become a close friend (of). øøchummy adj. (chummier, chummiest). chummily adv. chumminess n. [17th c.: prob. short for chamber-fellow]