Meaning

noun indicator provided by the stationary arm whose shadow indicates the time on the sundial

originBorrowed from French gnomon, or directly from its etymon Latin gnōmōn, or directly from its etymon Ancient Greek γνώμων (gnṓmōn, “discerner, interpreter; carpenter’s square; gnomon of a sundial; (geometry) gnomon”), from γιγνώσκω (gignṓskō, “to be aware of; to perceive; to know”), ultimately from Proto-Indo-European *ǵneh₃- (“to know”); the word is thus related to know. The geometry sense (sense…

Etymology from Wiktionary, CC BY-SA 3.0