The generic name comes from Latin jūglans, meaning 'walnut, walnut tree'. Jūglans is commonly said to be a contraction of Jōvis glans, 'nut of [the god] Jupiter'.. But a walnut kernel is in two halves joined by a thin neck, which easily breaks when the nut is extracted from its shell, and thus Verrius Flaccus called it iugulandam (a gerundive, = whose throat must be cut), because it is nearly separated in the middle; see Sextus Pompeius Festus. Or from iugum glans = yoke nut?