1. (noun)cos lettuce, romaine lettuce, Lactuca sativa longifolia lettuce with long dark-green spoon-shaped leaves Synonyms: cos, romaine, romainelettuce, cos lettuce
2. (noun)cos, cos lettuce, romaine, romaine lettuce lettuce with long dark-green leaves in a loosely packed elongated head Synonyms: cosine, romaine, romainelettuce, cos lettuce, cos