erythrocyte vs RBC

erythrocyte and RBC both are nouns.

Word	Noun	Adjective	Verb	Adverb
erythrocyte	Yes	No	No	No
RBC	Yes	No	No	No

As nouns, erythrocyte and RBC are synonyms defined as:

erythrocyte and RBC: a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus

Other synonyms of erythrocyte include red blood cell.

erythrocyte (noun)	RBC (noun)
a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus	a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus