columella >> /ˌkɑl(j)əˈmɛlə/
Definition: [noun] An ossicle of the middle ear of birds, reptiles, and amphibians.
Example: In amphibians, the columella shares the oval window with a second bone, the operculum, which communicates by way of an opercular muscle with the pectoral girdle.
Definition: [noun] The axis of a spiral shell.
Example: The attachment site of the large Crepidula on the ventral side of the host shell and the presence of algal or sponge borings through the columella of the host indicate that the Oliva shell was possibly occupied by a hermit crab.
Definition: [noun] The axis of the spore-producing body of some lower plants.
Example: The primary, stout capillitial branches arise from the upper part of the columella, dichotomously branching into flexuose threads.