spicule > define

noun

• Small pointed structure serving as a skeletal element in various marine and freshwater invertebrates e. G. Sponges and corals.
  • synonyms: spiculum

• (n.) Any small calcareous or siliceous body found in the tissues of various invertebrate animals, especially in sponges and in most Alcyonaria.
• (n.) A minute, slender granule or point.
• (n.) Same as Spicula.