Note: The assumption here is that the initial long vowel of āridus is shortened in ardēre, though this is uncertain. (Ernout and Meillet in Dictionnaire étymologique de langue latine marked it as long, though M. Leumann in Lateinische Laut- und Formenlehre considered it to have been shortened.) Although derivation of ardēre from āridus seems likely on a morphological basis, the semantic relation is anomalous, as the verb is not a stative derivative of the adjective—the verb ārēre "to be dry, parched" already serves that function. The noun ardor is similarly anomalous. Most other stative verbs in -ēre paired with adjectives in -idus have a corresponding abstract noun ending in -ōr-, -or (originally *-ōs-, *-ōs), but the pair āridus/ārēre lacks a corresponding noun *āror. The derivative ardor does not provide it, as it means "burning, fierce heat," not "dryness" (though heat produces dryness, the implicit semantic connection).