Pronunciation: (pru-gresh'un), [key]
1. the act of progressing; forward or onward movement.
2. a passing successively from one member of a series to the next; succession; sequence.
3. Math.a succession of quantities in which there is a constant relation between each member and the one succeeding it. Cf. arithmetic progression, geometric progression, harmonic progression.
4. Music.the manner in which chords or melodic tones follow one another; a succession of chords or tones.
5. Astrol.any of a variety of methods of comparing the natal chart to subsequent planetary positions in order to establish an optimum time to accomplish things or to establish the probable time an event occurred or will occur.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.