late 14c., aournen, later adornen, "to decorate, embellish," also "be an ornament to," from Old French aorner "to order, arrange, dispose, equip; adorn," from Latin adornare "equip, provide, furnish;" also "decorate, embellish," from ad "to" (see ad-) + ornare "prepare, furnish, adorn, fit out," from stem of ordo "row, rank, series, arrangement" (see order (n.)). The -d- was reinserted by French scribes 14c. and in English from late 15c. Related: Adorned; adorning.