Definition of: progression

(prə·gresh′ən) noun
1. The act of progressing; advancement.
2. Math. A sequence of numbers or quantities each of which is derived from the preceding by a constant law. See ARITHMETIC PROGRESSION, GEOMETRIC PROGRESSION, SERIES (def. 2).
3. Music a An advance from one tone or chord to another, b A sequence or succession of tones or chords.
4. Course or lapse of time; passage. See synonyms under PROGRESS. [<L progressio, -onis]
—pro·gres′sion·al adjective
—pro·gres′sion·ism noun