surrogation (n.)

1530s, from Medieval Latin surrigationem (nominative surrogatio), noun of action from past participle stem of Latin surrogare/subrogare "put in another's place, substitute," from assimilated form of sub "in the place of, under" (see sub-) + rogare "to ask, propose," apparently a figurative use of a PIE verb meaning literally "to stretch out (the hand)," from root *reg- "move in a straight line."