su·per·sede also su·per·cede 
(s′pər-sēd)
(s′pər-sēd)tr.v. su·per·sed·ed, su·per·sed·ing, su·per·sedes or su·per·ced·ed or su·per·ced·ing or su·per·cedes
1. To take the place of; replace or supplant: "[Dean] Acheson's conversion, that military force should supersede diplomatic response as the core of U.S. foreign policy, would reverberate across generations" (James Carroll).
2. To take the place of (a person), as in an office or position; succeed. See Synonyms at replace.
[Late Middle English (Scottish) superceden, to postpone, defer, from Old French superceder, from Latin supersedēre, to sit on top of, abstain from : super-, super- + sedēre, to sit; see sed- in the Appendix of Indo-European roots.]
su′per·seder, su′per·ceder n.
su′per·session, su′per·cession (-sĕshən) n.
Usage Note: Supersede is commonly spelled supercede, probably by influence of words like accede and intercede. The spelling with a c has been in existence for 300 years and has traditionally been considered an error, but it appears so widely in books and other edited publications that this spelling must be considered standard.