D defs.my
Entry 4 senses Webster, 1913

Progression

/prəg-rĕsh'-ən/ · Pro·gres·sion · IPA /pɹəˈɡɹɛʃən/
01 n. The act of moving forward; a proceeding in a course; motion onward.
  1. 1.
    The act of moving forward; a proceeding in a course; motion onward.
  2. 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. 3.
    Regular or proportional advance in increase or decrease of numbers; continued proportion, arithmetical, geometrical, or harmonic.(Math.)
  4. 4.
    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.(Mus.)