segment (n.) Look up segment at Dictionary.com
1560s, from Latin segmentum "a strip or piece cut off, a cutting, strips of colored cloth," from secare "to cut" (see section (n.)), with euphonious alteration of -c- to -g- before -m-. Latin segmentum was used in Medieval Latin as a geometry term, translating Greek tmema, and the word was first picked up in English in this sense. Meaning "segmental portion of anything circular" is from 1640s; general sense of "a division, section" is from 1762.
segment (v.) Look up segment at Dictionary.com
1859, intransitive, in reference to cell division, from segment (n.). Transitive sense, "divide (something) into segments" is from 1872. Related: Segmented; segmenting.