Pro*gres"sion (?), n. [L. progressio: cf. F. progression.]
1.
The act of moving forward; a proceeding in a course; motion onward.
2.
Course; passage; lapse or process of time.
I hope, in a short progression, you will be wholly immerged in the delices and joys of religion.
Evelyn.
3. Math.
Regular or proportional advance in increase or decrease of numbers; continued proportion, arithmetical, geometrical, or harmonic.
4. Mus.
A regular succession of tones or chords; the movement of the parts in harmony; the order of the modulations in a piece from key to key.
Arithmetical progression, a progression in which the terms increase or decrease by equal differences, as the numbers 2, 4, 6, 8, 1010, 8, 6, 4, 2
-- Geometrical progression, a progression in which the terms increase or decrease by equal ratios, as the numbers 2, 4, 8, 16, 32, 6464, 32, 16, 8, 4, 2
-- Harmonic progression, a progression in which the terms are the reciprocals of quantities in arithmetical progression, as
© Webster 1913.