WordNet sense 1 ((geometry) the area created by a plane cutting through a solid):

plane section

WordNet sense 2 (a specialized division of a large organization):

department

WordNet sense 3 (a self-contained part of a larger composition (written or musical)):

subdivision

WordNet sense 4 (one of the portions into which something is regarded as divided and which together constitute a whole):

division, part

WordNet sense 5 (one of several parts or pieces that fit with others to constitute a whole object):

segment, segment

WordNet sense 6 (the cutting of or into body tissues or organs (especially by a surgeon as part of an operation)):

incision, surgical incision