supersession (n.)

mid-15c., Scottish, "postpone, defer," from French superceder "desist, delay, defer," from Latin supersedere literally "sit on top of;" also, with ablative, "stay clear of, abstain from, forbear, refrain from," from super "above" (see super-) + sedere "to sit," from PIE root *sed- (1) "to sit." Meaning "displace, replace" first recorded 1640s. Related: Superseded; superseding.