Jupiter (mythology) practice of swearing by Jove to witness an oath in law courts is the origin of the expression "by Jove!"—archaic, but still in use. The name of the god was also adopted as the name of the planet Jupiter; the adjective "jovial" originally described those born under the planet of Jupiter (reputed to be jolly, optimistic, and buoyant in temperament). Jove was the original namesake of Latin forms of the weekday now known in English as Thursday (originally called "Iovis Dies" in Latin). These became "jeudi" in French, "jueves" in Spanish, "joi" in Romanian, "giovedì" in Italian, "dijous" in Catalan,
Pluto (mythology) Enraged"), in which Father Dis, the Roman counterpart of Pluto, uses a three-pronged spear to drive off Hercules as he attempts to invade the underworld. Seneca calls Dis the "Infernal Jove" or the "dire Jove" (the Jove who gives dire or ill omens, "dirae)", just as in the Greek tradition, "Plouton" is sometimes identified as a "chthonic Zeus." That the trident and bident might be somewhat interchangeable is suggested by a Byzantine scholiast, who mentions Poseidon being armed with a bident. In the Middle Ages, classical underworld figures began to be depicted with a pitchfork. Early Christian writers had identified