"resembling an oyster," 1840, with -an + Latinized form of Greek ostrakios, from ostreion "oyster," from PIE *ost-r-, from root *ost- "bone." Related ostraceous (by 1834).
osteoporosis
ostinato
ostler
Ostmark
ostomy
ostracean
ostracise
ostracism
ostracize
ostrich
Ostrogoth
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