c.1400, from O.Fr. augmenter (14c.), from L.L. augmentare "to increase," from L. augmentum "an increase," from augere "to increase, make big, enlarge, enrich," from PIE base *aug- "to increase" (cf. Skt. ojas- "strength;" Lith. augu "to grow," aukstas "high, of superior rank;" Gk. auxo "increase," auxein "to increase;" Goth. aukan "to grow, increase;" O.E. eacien "to increase").