Merriam-Webster's Collegiate® Dictionary, 11th Edition
SEGMENT
I. noun see: saw
Date: 1570
a portion cut off from a geometric figure by one or more points, lines, or planes: as, the area of a circle bounded by a chord and an arc of that circle, the part of a sphere cut off by a plane or included between two parallel planes, the finite part of a line between two points in the line,
2. a separate piece of something ; bit , fragment , one of the constituent parts into which a body, entity, or quantity is divided or marked off by or as if by natural boundaries , see: part segmentary adjective
II. transitive verb
Date: 1859
to separate into segments ; give off as segments