1540s, "to exist;" c.1600, "retain the existing state," from Middle French subsister and directly from Latin subsistere "to stand still or firm, take a stand, take position; abide, hold out," from sub "under, up to" (see sub-) + sistere "to assume a standing position, stand still, remain; set, place, cause to stand still" (see assist, v.). Meaning "to support oneself" (in a certain way) is from 1640s. Related: Subsisted; subsisting.