spicule
/ˈspɪkjuːl/
noun
- A small, needle-like structure, especially in biology (e.g., in sponges, sea cucumbers, or plants) or in astronomy (a jet of gas in the sun's atmosphere).
- Solar spicules shoot up from the sun's surface and can be seen during an eclipse.
- Under the microscope, the spicule of the sea cucumber appeared as a delicate rod.
- The sponge's skeleton is made of tiny spicules that give it support.