'Supersession' definitions:

Definition of 'supersession'

From: WordNet
noun
Act of replacing one person or thing by another especially one held to be superior [syn: supersedure, supersession]

Definition of 'Supersession'

From: GCIDE
  • Supersession \Su`per*ses"sion\, n. [Cf. OF. supersession. See Supersede.] The act of superseding, or the state of being superseded; supersedure. [1913 Webster]
  • The general law of diminishing return from land would have undergone, to that extent, a temporary supersession. --J. S. Mill. [1913 Webster]