progression (n.)

late 14c., "action of moving from one condition to another," from Old French progression and directly from Latin progressionem (nominative progressio) "a going forward, advancement, growth, increase," noun of action from past participle stem of progredi "go forward," from pro "forward" (see pro-) + gradi "to step, walk," from gradus "a step" (from PIE root *ghredh- "to walk, go").