1630s, "to make larger, increase," from French agrandiss-, present participle stem of agrandir "to augment" (16c.), ultimately from Latin ad "to" (see ad-) + grandire "to make great," from grandis (see grand (adj.)). The double -g- spelling in English is by analogy with Latin words in ad-. Related: Aggrandized; aggrandizing.[aggrandize etymology, aggrandize origin, 英语词源]