Emily Dickinson Lexicon

MOUNT'E-BANK, n. [It. montare, to mount, and banco, bench.]

1. One who mounts a bench or stage in the market or other public place, boasts of his skill in curing diseases, vends medicines which he pretends are infallible remedies, and thus deludes the ignorant multitude. Persons of this character may be indicted and punished.
2. Any boastful and false pretender. Nothing so impossible in nature, but mountebanks will undertake. Arbuthnot.