segment

Concise Oxford English Dictionary © 2008 Oxford University Press:
segment /ˈsɛgm(ə)nt/

▶noun

• 1 each of the parts into which something is or may be divided.

• 2 Geometry a part of a circle cut off by a chord, or a part of a sphere cut off by a plane not passing through the centre.

• 3 Phonetics the smallest distinct part of a spoken utterance, especially with regard to vowel and consonant sounds.

• 4 Zoology each of a series of similar anatomical units of which the body and appendages of some animals are composed.

▶verb usu. /sɛgˈmɛnt/ 

• 1 divide into segments.

• 2 Embryology (of a cell) undergo cleavage.

– derivatives
segmentary adjective,
segmentation noun,
segmented adjective.

– origin C16: from L. segmentum, from secare ‘to cut’.