10 letters · 19 points in Scrabble
noun the cardinal number that is the sum of three and one
originFrom Middle English quaterniǒun, from Late Latin quaterniō, from quaternī (“four each”) + -iō, from quater (“four times”). Doublet of kern. The mathematics sense was coined by Irish mathematician and astronomer William Rowan Hamilton in 1843.
Etymology from Wiktionary, CC BY-SA 3.0