Origin uncertain. Possibly from a dissimilation of an unattested Proto-Italic *gnōrjā, through *gnoris (“knowledge”) (compare Ancient Greek γνώριμος (gnṓrimos, “well-known, familiar”)), from Proto-Indo-European *ǵneh₃- (“to know, recognize”). For the dissimilation compare grōma from Ancient Greek γνῶμα (gnôma). Cognate with gnāvus, gnārus, ignōrō (with no dissimilation), nārrō, and also nōscō.