FromProto-Italic*knuks, from a root*knu- also found inProto-Celtic*knūs (source ofIrishcnó) andProto-Germanic*hnuts (source ofEnglishnut). Based on the form of the nouns and the restriction of the root to Germanic, Celtic and Italic, it has been argued to be of non-Indo-European origin. De Vaan suggests that it is related tonūgae(“trifles”).[1]
^De Vaan, Michiel (2008) “nux”, inEtymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill,→ISBN,page420
“nux”, inCharlton T. Lewis and Charles Short (1879)A Latin Dictionary, Oxford: Clarendon Press
“nux”, inCharlton T. Lewis (1891)An Elementary Latin Dictionary, New York: Harper & Brothers
"nux", in Charles du Fresne du Cange’sGlossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)