"claim or demand presumptuously," 1530s, from Latin arrogatus, past participle of arrogare "to claim for oneself," from assimilated form of ad "to" (see ad-) + rogare "to ask, to propose (a law, a candidate); to ask a favor, entreat, request," apparently a figurative use of a PIE verb meaning literally "to stretch out (the hand)," from *rog-, variant of the root *reg- "move in a straight line." Related: Arrogated; arrogating.