Mer’ • cer [Middle English, from Old French mercier, trader, frommerz, merchandise, from Latin merx, merc-, merchandise.] A dealer in textiles, especially silks. Soho’s Mercer Street, which runs for 12 blocks from Canal St. north to East 8th just west of Broadway, was actually named for Revolutionary War general Hugh Mercer (as was New Jersey’s Mercer County, seat of its capital, Trenton) [...]