| Noun | 1. | genus Ostrea - type genus of the family Ostreidae mollusk genus - a genus of mollusks family Ostreidae, Ostreidae - oysters blue point, bluepoint - small edible oyster typically from the southern shore of Long Island Japanese oyster, Ostrea gigas - a large oyster native to Japan and introduced along the Pacific coast of the United States; a candidate for introduction in Chesapeake Bay |