1each of the parts into which something is or may be divided: a large segment of the local population orange segments the market for private cars can be broken down into several segments a portion of time allocated to a particular broadcast item on radio or television: they probably want to tape you for the eleven o’clock segment a separate broadcast item, typically one of a number that make up a particular programme: Hammond and the others were filming a segment for his programme 2 Geometry a part of a figure cut off by a line or plane intersecting it, in particular: the part of a circle enclosed between an arc and a chord. the part of a line included between two points. the part of a sphere cut off by any plane not passing through the centre. 3 Zoology each of the series of similar anatomical units of which the body and appendages of some animals are composed, such as the visible rings of an earthworm’s body.
4 Phonetics the smallest distinct part of a spoken utterance, especially with regard to vowel and consonant sounds rather than stress or intonation.
divide (something) into separate parts or sections:the unemployed are segmented into two groups [no object] divide into separate parts or sections:the market is beginning to segment into a number of well-defined categories [no object] Embryology (of a cell) undergo cleavage; divide into many cells.