plural: [14] Plural is one of a range of English words that go back ultimately to Latin plūs ‘more’, a descendant (like English full and Greek pólus ‘much’, source of the English prefix poly-) of the Indo-European base *plē- ‘full’. This was borrowed into English directly as plus [17], in the sense ‘with the addition of’. Plural comes via Old French plurel from the Latin derivative plūrālis ‘more than one’.
Other related words in English include nonplus [16] (etymologically ‘put in a position where “no more” – Latin nōn plūs – can be done’); pluperfect [16] (a lexicalization of the Latin phrase plūs quam perfectum ‘more than perfect’); and surplus. => nonplus, pluperfect, plus, surplus[plural etymology, plural origin, 英语词源]