Wing IV · Semantic lineage
mercury
Oldest known meaning — the god Mercury, divine messenger and patron of trade.
the god → the planet → the quick metal → a changeable temperament
Excavation timeline
How the meaning shifted
Etymological strata
Layers of descent
- MercuriusLatin · classical
Latin — god of commerce, eloquence and travel (from merx, merchandise)
- MercuriusLatin / Medieval · —
Latin — the planet; and, by alchemy, quicksilver
- mercurieMiddle English · 14c.
Middle English — the metal quicksilver; the planet
- mercurialModern English · 1600s
English — volatile, changeable in temperament
Constellation
Descendants & cognates
Inner ring — modern descendants of the same root. Outer ring — cognates in sister languages. Gold descendants link to their specimen.
Semantic drift
How the sense moved
Mercury chains god → planet → metal → mood. The god (from merx, 'goods' — hence merchant, commerce, market) was quick and shifty; the fastest planet took his name; the only liquid metal, restless and quick, took it next; and a 'mercurial' person inherited all of that restlessness. One root binds the marketplace, the sky, the laboratory and the psyche.
Metaphorical expansion
Where the word reaches now
Cultural sediment
The worldview inside the word
Mercury is a fossil of the old correspondence between gods, planets, metals and humours — a single cosmos where everything mirrored everything.
Related descendants
Words from the same root
Sources
Confidence & citations
Lineage confidence · Well attested
- · Online Etymology Dictionary
- · OED, s.v. mercury, mercurial