late 14c., "a going on, action of walking forward," from Old French progres (Modern French progrès), from Latin progressus "a going forward," from past participle of progredi "go forward," from pro "forward" (see pro-) + gradi "to step, walk," from gradus "a step" (from PIE root *ghredh- "to walk, go").
In early use in English especially "a state journey by royalty." Figurative sense of "growth, development, advancement to higher stages" is from c. 1600. To be in progress "underway" is attested by 1849. Progress report attested by 1865.