hype man
n.— «Hype-men, for those of you unfamiliar with the lingo, are the fellas you see at rap shows who stand next to MCs and bellow certain words along with the rap to add emphasis.» —“I Love a Parade: Radar Station hitches a ride with great big rappers” by Jordan Harper Riverfront Times (St. Louis, Mo.) May 26, 2004. (source: Double-Tongued Dictionary)
Further reading
A flashlight doesn’t flash. It provides a steady beam of light. So why is it called a flashlight? The earliest versions lit up only briefly before the batteries gave out and required a recharge, so they were literally “flash lights...
Chris from Kittery, Maine, wonders about the colloquial expression no sirree, Bob! or yes sirree, Bob!, which is an emphatic way of saying “definitely not!” or “no way!” The sirree (sometimes spelled with one r, as siree) in...