(n)a procedure in which blood is drawn and separated into its components by dialysis; some are retained and the rest are returned to the donor by transfusion, Syn.pheresis
The Collaborative International Dictionary of English (GCIDE) v.0.53Collaborative International Dictionary (GCIDE)
n. [ L. aphaeresis, Gr. &unr_;, fr. &unr_; to take away; &unr_; + &unr_; to take. ] 1. (Gram.) The dropping of a letter or syllable from the beginning of a word; e. g., cute for acute. [ 1913 Webster ]
2. (Surg.) An operation by which any part is separated from the rest. [ Obs. ] Dunglison. [ 1913 Webster ]