hemoglobin (n.) Look up hemoglobin at Dictionary.com
also hæmoglobin, coloring matter in red blood cells, 1862, shortening of hæmatoglobin (1845), from Greek haimato-, comb. form of haima (genitive haimatos) "blood" (see -emia) + globulin, a type of simple protein, from globule, formerly a word for "corpuscle of blood."