What is the origin of ostracize?

Ostracize “to exclude from society” derives from Ancient Greek ostrakízein “to banish,” from óstrakon “potsherd, tile, ballot” and the verbal suffix -izein “-ize.” The original sense of ostrakízein involved banishing a person by voting that was conducted by using potsherds as ballots, hence the verb’s derivation. Though ostracize resembles ostrich, the flightless bird, in spelling and pronunciation, the two words are unrelated; instead, ostracize descends from a Proto-Indo-European root meaning “bone” that is also found in osteoporosis, a common bone disease; oyster, because of the hardness of the shell; and, from Latin, the adjective osseous “bony.” Ostracize was first recorded in English in the 1640s.