n. [ F. madrepore, perh. fr. madré spotted, fr. OF. madre, mazre, a kind of knotty wood with brown spots, fr. OHG. masar a knot, grain, or vein in wood, a speck, G. maser + pore (see Pore); or perh. F. madrépore is rather from It. madrepora, and this perh. fr. It. madre mother (see Mother) + Gr. &unr_; a soft stone. ] (Zool.) Any coral of the genus Madrepora, a group of corals having calcareous skeletons aggregations of which form reefs and islands; formerly, often applied to any stony coral.
Syn. -- stony coral, madriporian coral. [ 1913 Webster ]