a person who sells quack medicines, as from a platform in public places, attracting and influencing an audience by tricks, storytelling, etc.
2.
any charlatan or quack.
–verb (used without object)
3.
to act or operate as a mountebank.
Origin: 1570–80; (< MF) < It montimbanco one who climbs on a bench, equiv. to mont(are) to climb (see mount1) + -im-, var. of in on + banco bench (see bank2)
"a doctor that mounts a bench in the market, and boasts his infallible remedies and cures" [Johnson], 1577, from It. montambanco, contraction of monta in banco "quack, juggler," lit. "mount on bench" (to be seen by crowd), from monta, imperative of montare "to mount" + banco, var. of banca "bench."
Main Entry: moun·te·bank Pronunciation: 'maunt-i-"ba[ng]k Function: noun : an itinerant hawker of pills and patent medicines especially from aplatform :QUACKmountebank —Shak.>
[moun-tuh-bangk] 
təˌbæŋk