suffix forming nouns: 1 in collective numerals (myriad; triad). 2 in fem. patronymics (Dryad). 3 in names of poems and similar compositions (Iliad; Dunciad; jeremiad).
[ Gk -as -ada ]
AD
Meaning of AD in English
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012