13 letters · 20 points in Scrabble
noun measuring instrument for measuring the refractive index of a substance
originEtymology tree English refract Ancient Greek -ο- (-o-)der. Latin -o-bor. English -o- Proto-Indo-European *meh₁- Proto-Indo-European *-tḗr Proto-Indo-European *-trom Proto-Hellenic *-tron Ancient Greek -τρον (-tron) Ancient Greek μέτρον (métron)der. English -meter English refractometer From refract + -o- + -meter.
Etymology from Wiktionary, CC BY-SA 3.0