Meaning of -ES' in English

(ə̇)z noun plural suffix

Etymology: Middle English, -es, from -e, older gen. plural ending (from Old English -a ) + -s, gen. singular ending — more at -'s

— used to form the plural possessive of most nouns that end in s, z, sh, ch, or postconsonantal y and of some nouns ending in f

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.