Merriam-Webster Collegiate Dictionary - oregano

 noun  Etymology: American Spanish oregano, from Spanish, wild marjoram, from Latin origanum — more at origanum  Date: 1771  1. a bushy perennial mint (Origanum vulgare) that is used as a seasoning and a source of aromatic oil — called also origanum, wild marjoram  2. any of several plants (genera Lippia and Coleus) other than ~ of the vervain or mint families