The fact that, under certain hypotheses, the homology of a space relative to a subspace is unchanged by the identification of a subspace of the latter to a point
the omission that is made when an editorial change shortens a written passage; "an editor's deletions frequently upset young authors"; "both parties agreed on the excision of the proposed clause"
the act of banishing a member of the Church from the communion of believers and the privileges of the Church; cutting a person off from a religious society