◙ noun 1. [mass noun] a hard stony substance secreted by certain marine coelenterates as an external skeleton, typically forming large reefs in warm seas • 珊瑚 »[as modifier] a coral reef. 珊瑚礁。 precious red coral, used in jewellery • （作为珠宝的）珊瑚宝石 the pinkish-red colour of red coral • 珊瑚红 2. a sedentary coelenterate of warm and tropical seas, with a calcareous, horny, or soft skeleton. Most corals are colonial and many rely on the presence of green algae in their tissues to obtain energy from sunlight • 珊瑚虫 3. Several orders in the class Anthozoa, including the ‘true’ or stony corals (order Scleractinia or Madreporaria), which form reefs, the soft corals (order Alcyonacea), and the horny corals (order Gorgonacea) • 珊瑚虫纲的几个目，包括形成珊瑚礁的石珊瑚目，以及软珊瑚目和柳珊瑚目 4. [mass noun] the unfertilized roe of a lobster or scallop, which is used as food and becomes reddish when cooked • 龙虾卵；扇贝卵