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 10 10 8 6 4 2] by the difference 2.
— Geometrical progression, a progression in which the terms increase or decrease by equal ratios, as the numbers [2 4 8 16 32 64 64 32 16 8 4 2] by a continual multiplication or division by 2.
— Harmonic progression, a progression in which the terms are the reciprocals of quantities in arithmetical progression, as ½, ¼, ⅙, ⅛, ⅟₁₀.