Are yams and sweet potatoes the same?
late 14c., from Old French plurel "more than one" (12c., Modern French pluriel), from Latin pluralis "of or belonging to more than one," from plus (genitive pluris) "more" (see plus). The noun meaning "a plural number" is from late 14c.
The grammatical category in nouns, pronouns, and verbs that refers to more than one thing. Most nouns become plural with the addition of -s or -es: hats, chairs, dishes, countries, and so on. Some nouns form the plural in other ways, as in children, feet, geese, and women. (Compare singular; see agreement.)