crisphead lettuce vs iceberg

crisphead lettuce and iceberg both are nouns.

Word	Noun	Adjective	Verb	Adverb
crisphead lettuce	Yes	No	No	No
iceberg	Yes	No	No	No

As nouns, crisphead lettuce and iceberg are synonyms defined as:

crisphead lettuce and iceberg: lettuce with crisp tightly packed light-green leaves in a firm head

Other synonyms of crisphead lettuce include iceberg lettuce.

crisphead lettuce (noun)	iceberg (noun)
lettuce with crisp tightly packed light-green leaves in a firm head	lettuce with crisp tightly packed light-green leaves in a firm head
	a large mass of ice floating at sea; usually broken off of a polar glacier