ichor
The liquid said to flow in place of blood in the veins of the gods.
countable, uncountable
This ſaid, ſhe wip’d from Venus’ wounded Palm / The ſacred Ichor, and infus’d the Balm.
The blood of human beings or animals; also (obsolete) the clear, fluid portion of blood; blood plasma, plasma.
countable, uncountable
He had merely meant to express his feeling that the streams which ran through their veins were not yet purified by time to that perfection, had not become so genuine an ichor, as to be worthy of being called blood in the genealogical sense.
A blood-like fluid.
countable, figuratively, uncountable
[I]chores and thoſe ſerious matters being thickned become flegme, and flegme degenerates into choler, choler aduſt becomes æruginoſa melancholia, as vinegar out of the pureſt wine putrified or by exhalation of purer ſpirits is ſo made, and becomes ſowre and ſharp; […]
A fluid believed to seep out from magma and cause rock to turn into granite.
archaic, countable, uncountable
Where it comes from
Sense 1 (“liquid said to flow in place of blood in the veins of the gods”) is borrowed from Medieval Latin ichor, from Ancient Greek ῑ̓χώρ (īkhṓr, “fluid running through the veins of gods, ichor; watery part of blood, lymph, serum; watery part of milk, whey; gravy; pus; naphtha”); further etymology unknown, probably from Pre-Greek. Sense 2.4 (“fetid, watery discharge from a sore”) is from Middle English icor, icore [and other forms], from Medieval Latin ichor; see further above.
Adapted from the Wiktionary entry ichor (CC BY-SA 4.0).