(1):

(n.) One of the transverse partitions dividing the body cavity of an annelid.

(2):

(n.) One of the radial calcareous plates of a coral.

(3):

(n.) A wall separating two cavities; a partition; as, the nasal septum.

(4):

(n.) One of the transverse partitions dividing the shell of a mollusk, or of a rhizopod, into several chambers. See Illust. under Nautilus.

(5):

(n.) A partition that separates the cells of a fruit.