Mid 16th century (in an earlier sense). Partly from Middle French profection (French profection) system of prediction based on the zodiac, progression, progression (of a star) from classical Latin prōfect-, past participial stem of prōficere to make headway, to advance, progress + French -ion, and partly from Middle French profection act of setting out (of an army) and its etymon classical Latin profectiōn-, profectiō action of setting out, departure from profect-, past participial stem of proficīscī to set out, start + -iō.