from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Pertaining to grammatical number (as in singular and plural), referring to two or more of something; nonsingular.
- n. duoplural number; the grammatical number of a noun marking two or more of something (as in singular or duoplural). Some languages that employ the duoplural are Navajo and Taos, where the verb shows singular, dual, and plural numbers, but the nouns are marked only as singular or nonsingular (duoplural).
dual + plural (Wiktionary)