cos lettuce vs romaine lettuce

cos lettuce and romaine lettuce both are nouns.

Word	Noun	Adjective	Verb	Adverb
cos lettuce	Yes	No	No	No
romaine lettuce	Yes	No	No	No

As nouns, cos lettuce and romaine lettuce are synonyms defined as:

cos lettuce and romaine lettuce: lettuce with long dark-green leaves in a loosely packed elongated head

Other synonyms of cos lettuce include cos, romaine.

As nouns, cos lettuce and romaine lettuce are synonyms defined as:

cos lettuce and romaine lettuce: lettuce with long dark-green spoon-shaped leaves

Other synonyms of cos lettuce include Lactuca sativa longifolia.

cos lettuce (noun)	romaine lettuce (noun)
lettuce with long dark-green leaves in a loosely packed elongated head	lettuce with long dark-green leaves in a loosely packed elongated head
lettuce with long dark-green spoon-shaped leaves	lettuce with long dark-green spoon-shaped leaves