WordNet (r) 3.0 (2006):

erythrocyte
    n 1: a mature blood cell that contains hemoglobin to carry
         oxygen to the bodily tissues; a biconcave disc that has no
         nucleus [syn: red blood cell, RBC, erythrocyte]

Moby Thesaurus II by Grady Ward, 1.0:

52 Moby Thesaurus words for "erythrocyte":
   Rh factor, Rh-negative, Rh-positive, Rh-type, Rhesus factor,
   antibody, antigen, arterial blood, blood, blood bank, blood cell,
   blood count, blood donor, blood donor center, blood group,
   blood grouping, blood picture, blood platelet, blood pressure,
   blood serum, blood substitute, bloodmobile, bloodstream,
   circulation, clinical dextran, dextran, globulin, gore, grume,
   hematics, hematologist, hematology, hematoscope, hematoscopy,
   hemocyte, hemoglobin, hemometer, humor, ichor, isoantibody,
   leukocyte, lifeblood, neutrophil, opsonin, phagocyte, plasma,
   plasma substitute, red corpuscle, serum, type O, venous blood,
   white corpuscle