bread vs lettuce

bread and lettuce both are nouns.

Word	Noun	Adjective	Verb	Adverb
bread	Yes	No	Yes	No
lettuce	Yes	No	No	No

As nouns, bread and lettuce are synonyms defined as:

bread (noun)	lettuce (noun)
food made from dough of flour or meal and usually raised with yeast or baking powder and then baked	leaves of any of various plants of Lactuca sativa
informal terms for money	any of various plants of the genus Lactuca
	informal terms for money

bread (verb)	lettuce (verb)
cover with bread crumbs