a plural suffix occurring in loanwords from Greek:
Hyades.
Origin
< Greek-es
-es2
1.
variant of -s2. in verbs ending in s, z, ch, sh, or post-consonantal y: passes; buzzes; pitches; dashes; studies.
-es3
1.
variant of -s3. in nouns ending in s, z, ch, sh, or post-consonantal y, and in nouns in f with v in the plural:
losses; fuzzes; riches; ashes; babies; sheaves.
British Dictionary definitions for -es
-es
suffix
1.
for nouns ending in ch, s, sh, z, postconsonantal y, for some nouns ending in a vowel, and nouns in f with v in the plural, a variant of -s1ashes, heroes, calves
2.
for verbs ending in ch, s, sh, z, postconsonantal y, or a vowel, a variant of -s1preaches, steadies, echoes
-s1
suffix
1.
forming the plural of most nouns: boys, boxes
Word Origin
from Old English -as, plural nominative and accusative ending of some masculine nouns
-s2
suffix
1.
forming the third person singular present indicative tense of verbs: he runs, she washes
Word Origin
from Old English (northern dialect) -es, -s, originally the ending of the second person singular