The strange wistfulness of used bookshops, which feel simultaneously cosy and melancholy, as though the shelves are stacked with the ambitions of people now dead.

Coined by John Koenig, blending the Latin vellum — the parchment used in ancient books — with ichor, the ethereal fluid said to flow in the veins of the gods.

A companion emotion to kenopsia, the eerie atmosphere of a place that is usually crowded but is now abandoned.

Part of Koenig's broader project of filling emotional gaps in the English language with invented but linguistically coherent neologisms.

The word gained particular traction after a 2015 viral Tumblr post, becoming one of the most widely shared entries from the Dictionary of Obscure Sorrows.