Wiktionary
paenultima law
n. (context philology and orthoëpy sometimes “the paenultima law of accentuation” English) The (l en rule) of (l en Classical Latin) pronunciation which states that a word receives (l en antepenultimate) stress if its (l en penult) is a short or metrically light (l en syllable), but receives (l en penultimate) stress if its penult is a long or metrically heavy syllable.