Definition from Wiktionary, the free dictionary
ـُونَ • (-ūna) m
- Nominative-case (marfūʿ) suffix used to pluralize masculine nouns and adjectives referring to people. In Classical Arabic, with full ʾiʿrāb, appears as ـُونَ (-ūna). Note that most masculine nouns and adjectives referring to people, especially shorter ones, are not pluralized in this fashion, but use a broken plural instead. Furthermore, non-human masculine nouns don't use this suffix, either forming a broken plural or using the "feminine" suffix ـَات (-āt).
- Nominative-case (marfūʿ) suffix used very occasionally to pluralize non-human nouns, including some that are feminine, such as سَنَة (sana, “year”), plural سِنُون (sinūn).
- ـِينَ (-īna) (for the accusative and genitive cases)
ون • (van)
ـون • (-un)
- (rare, literary) A suffix forming the plural of nouns (usually of Arabic origin) ending in ـی (-i)