An Etymological Dictionary of Astronomy and Astrophysics

The red liquid that circulates in the arteries and veins of humans and other vertebrate animals, carrying oxygen to and carbon dioxide from the tissues of the body (OxfordDictionaries.com).

Etymology (EN): M.E. blo(o)d, O.E. blôd; akin to O.Frisian, O.Saxon blôd, O.H.G. bluot (Ger. Blut), Gothic bloth.

Etymology (PE): Xun, from Mid.Pers. xûn; cf. Sogd. xurn, Khotanese hûna, Yaghnobi waxin, Av. vohunī,