emporium (n.) Look up emporium at Dictionary.com
1580s, "place of trade, mart," from Latin emporium, from Greek emporion "trading place, market," from emporos "merchant," originally "traveler," from assimilated form of en "in" (see en- (2)) + poros "passage, voyage," related to peirein "to pass through," from PIE root *per- (2) "to lead, pass over."

Greek emporos in the "merchant" sense meant especially "one who trades on a large scale, usually but not necessarily by sea" [Buck], as opposed to kapelos "local retail dealer, shopkeeper." Properly, a town which serves as the commercial hub of a region, but by 1830s American English "Grandiloquently applied to a shop or store" [Craigie].