megaloblast vs erythrocyte

megaloblast and erythrocyte both are nouns.

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

As nouns, erythrocyte is a hypernym of megaloblast; that is, erythrocyte is a word with a broader meaning than megaloblast:

megaloblast: abnormally large red blood cell present in pernicious anemia and folic acid deficiency
erythrocyte: a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus

Other hypernyms of megaloblast include RBC, red blood cell.

megaloblast (noun)	erythrocyte (noun)
abnormally large red blood cell present in pernicious anemia and folic acid deficiency	a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues; a biconcave disc that has no nucleus