curiosus

Back-formation from incūriōsus (“careless, negligent”) by deletion of the negative prefix in- (“un-”) in order to remain with the opposite meaning.

• (Classical Latin) IPA^(key): /kuː.riˈoː.sus/,
• (modern Italianate Ecclesiastical) IPA^(key): /ku.riˈo.sus/,

cūriōsus (feminine cūriōsa, neuter cūriōsum, comparative cūriōsior); first/second-declension adjective

1. Careful, diligent, thoughtful, devoted.
2. Elaborate, complicated.
3. That injures himself by care; careworn, emaciated, wasted, lean.
4. (in a good sense) Curious, inquisitive.
5. (in a bad sense) Meddlesome, officious, prying, interfering, curious, inquisitive.
   • 1st c. BC, Marcus Tullius Cicero, De Finibus Bonorum et Malorum :

     Etenim si delectamur cum scribimus, quis est tam invidus qui ab eo nos abducat? Sic isti curiosi, quos offendit noster minime nobis iniucundus labor.

     Indeed if I enjoy writing, who would be so spiteful as to keep me from it? Thus are these meddlesome individuals to whom this my not at all unpleasant (to me) endeavor is offensive.

First/second-declension adjective.

• cūriōsē
• cūriōsitās
• cūriōsulus
• incūriōsus

cūriōsus m (genitive cūriōsī); second declension

1. One who pries; a spy or scout; secret police, informer.

Second-declension noun.

• “curiosus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• curiosus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
• curiosus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.