late 14c., "to aid," also "to hold up, prop up, put up with, tolerate," from Old French suporter "to bear, endure, sustain, support" (14c.), from Latin supportare "convey, carry, bring up, bring forward," from assimilated form of sub "up from under" (see sub-) + portare "to carry," from PIE root *per- (2) "to lead, pass over." Related: Supported; supporting.
late 14c., "act of assistance, backing, help, aid," from support (v.). Meaning "that which supports, one who provides assistance, protection, backing, etc." is early 15c. Sense of "bearing of expense" is mid-15c. Physical sense of "that which supports" is from 1560s. Meaning "services which enable something to fulfil its function and remain in operation" (as in tech support) is from 1953.