- any of various small, columnlike structures of animals or plants; rod or axis.
- a small central column of sterile tissue within the sporangium of certain fungi, liverworts, and mosses.
- a small bone in the ear of amphibians, reptiles, and birds.
- biology
- the central part of the spore-producing body of some fungi and mosses
- any similar columnar structure
- a small rodlike bone in the middle ear of frogs, reptiles, and birds that transmits sound to the inner ear: homologous to the mammalian stapes
