A biting midge, gnat, or mosquito found in the Caribbean, especially in Jamaica and Barbados.
Origin
Mid 17th century; earliest use found in Richard Ligon (c1585–1662), business agent and natural science writer. From merry + wing, after Portuguese maruim (also in forms marigüi, maringuim, meruí, meruim, etc.) from Tupi mari'wi or a related form.