- division into segments.
- the subdivision of an organism or of an organ into more or less equivalent parts.
- cell division.
- the act or an instance of dividing into segments
- embryol another name for cleavage (def. 4)
- zoology another name for metamerism (def. 1)
n.1650s, “a cutting in small pieces;” 1851 of cells, from segment (v.) + -ation. n.