1Zoology. The middle lobe of the foot of a mollusc.

2Botany. Originally; the region of a leaf primordium corresponding to the petiole; the petiole itself. Later also: an internode between prophylls in certain compound inflorescences.

3Zoology. The section of a tetrapod limb (especially of an amphibian or reptile) constituted by the carpus (in the forelimb) or the tarsus (in the hind limb); the mesopodial bones collectively.