1. a chart or diagram using labeled blocks connected by straight lines to represent the relationship of parts or phases, as the steps in a data-processing application. Cf. flow chart (def. 2).
2. Geol.a perspective representation of the geology of an area showing surface contours and generally including two vertical cross sections.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.