plane [L, planum, level] , 1. n., a flat surface determined by three points in space. 2. n., an extension of a longitudinal section through an axis, such as the coronal, horizontal, transverse, frontal, and sagittal planes, used to identify the position of various parts of the body in the study of anatomy. 3. v., the act of paring or of rubbing away. 4. n., a superficial incision in the wall of a cavity or between tissue layers, especially in plastic surgery.
