(archaic or chiefly dialectal) A cornmerchant, especially one in Newcastle-upon-Tyne.
From booth + man. Cognate with Scotsbuthman (“a shop-keeper”). In some cases, such as translations of Norse sagas, use of the word (to mean "one who mans a booth") was probably reinforced by the cognate Old Norse búðarmaðr (Icelandic búðarmaður).
English Wiktionary. Available under CC-BY-SA license.