/ˈaɪkər/
[noun] In ancient Greek mythology, the golden fluid that flows through the veins of the gods instead of blood; in medicine, an old-fashioned word for a thin, unpleasant liquid that sometimes comes from a wound or ulcer.
The gods of ancient Greece didn't bleed — they leaked golden ichor, a fluid so divine it was literally poisonous to mortals.
The word ichor comes directly from the ancient Greek word ἰχώρ (ikhōr), a term the Greeks used to describe the ethereal fluid that ran through the veins of their immortal gods. Unlike human blood — red, warm, mortal — ichor was imagined as something altogether different: golden, rarefied, and charged with divine power. Homer used the word in the Iliad when the goddess Aphrodite is wounded in battle, and instead of blood, ichor flows from her injury. This single image captures one of the most striking ideas in Greek religion: that the gods were made of fundamentally different stuff than humans, and that difference ran all the way down to what moved inside them.
The Greek word ikhōr has no firmly established Proto-Indo-European root that scholars agree on, which makes it something of a linguistic mystery. Some researchers have suggested connections to words relating to moisture or fluid, while others believe it may have entered Greek from an older, pre-Greek Aegean language — one of the many words in Greek whose origins are lost to time. What is clear is that the ancient Greeks themselves treated it as a technical, almost clinical term alongside its mythological use, sometimes applying it to any thin, watery liquid seeping from the body.
The word entered the English language in the 17th century, arriving not through French or Latin as so many classical words did, but more directly from the original Greek, carried by scholars and physicians who read ancient texts in their original language. English writers at this time were deeply fascinated by classical mythology and medicine alike, and ichor served both worlds. In medical writing of the 1600s and 1700s, physicians used ichor — sometimes spelled ichor, sometimes ichour — to describe the thin, watery, foul-smelling discharge that oozed from infected wounds or ulcers. The word did double duty: poetic in literature, clinical in medicine.
This medical use reveals something wonderfully strange about the word's journey. In mythology, ichor was gloriously divine — golden, immortal, the mark of godhood. In medical English, it became associated with infection and decay, describing the most unpleasant kind of wound fluid imaginable. The same word that described the blood of Zeus was applied to the seeping of an infected sore. This reversal is not uncommon in the history of language — words travel between sacred and profane, between elevated and humble, often losing the prestige they began with.
In modern English, the medical sense of ichor has largely fallen out of everyday use, replaced by more precise clinical terminology. What remains is the mythological and literary sense, which never truly disappeared. Writers in the Romantic era revived ichor enthusiastically, and it became a favourite word of gothic and horror literature. H.P. Lovecraft, in particular, used ichor repeatedly to describe the strange fluids leaking from his monstrous, inhuman creatures — a perfect choice, since the word already carried the idea of something that flows inside beings who are not quite human. Today, ichor lives on most visibly in fantasy gaming and fiction, where it often describes the blood of demons, aliens, or supernatural creatures, keeping alive — perhaps without knowing it — the original Homeric idea of a fluid that marks the difference between mortal and immortal.