word-forming element meaning "plant, plant characteristic; planting, growth; abnormal growth," from Greek phyton "plant," literally "that which has grown," from phyein "to bring forth, make grow," from PIE root *bheue- "to be, exist, grow."
word-forming element of Greek origin appended to nouns and denoting collective numerals (triad, Olympiad) and fem. patronymics (Dryad, Naiad, also, in plural, Pleiades, Hyades), thence also plant family names; from Greek -as (genitive -ados), fem. suffix equivalent to -is.
From its use in Iliad (literally "of Ilion," that is, "Troy;" from Ilias poiesis or oidos "poem of Ilion," the accompanying noun being feminine, hence the termination) it has formed titles of poems in imitation of it (Columbiad, Dunciad).