Septum

·noun One of the radial calcareous plates of a coral.

II. Septum ·noun A partition that separates the cells of a fruit.

III. Septum ·noun A wall separating two cavities; a partition; as, the nasal septum.

IV. Septum ·noun One of the transverse partitions dividing the body cavity of an Annelid.

V. Septum ·noun One of the transverse partitions dividing the shell of a mollusk, or of a rhizopod, into several chambers. ·see ·Illust. under Nautilus.