Rainure
/ʁe.nyʁ/noun
A groove, channel, or narrow slot cut into a surface.
Did you know?French rainure is a real word, but its etymology is not securely established in standard references, so it’s treated as a later French technical term rather than a word with a clear ancient occult lineage.
Etymological Timeline
Modern French
French
rainure
“A groove, channel, or narrow slot cut into a surface.”
Old French
OF
rainure
“Likely a technical term for a groove or furrow, but the earlier history is uncertain.”
Late Medieval French
French
rainure
“A narrow cut, channel, or furrow in wood, metal, or stone.”
Modern English
English
rainure
“Borrowed technical term used in some contexts for a groove or channel.”