From calleō +‎ -idus.

• (Classical Latin) IPA^(key): [ˈkal.lɪ.dʊs]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈkal.li.dus]

callidus (feminine callida, neuter callidum, comparative callidior, superlative callidissimus, adverb callidē); first/second-declension adjective

1. wise, clever, ingenious

   Synonyms: sapiēns, prūdēns, sollers, vafer

   Antonyms: īnsipiēns, stupidus, fatuus, stultus, brūtus, āmēns, dēmēns

2. adroit, skilful, cunning, sly, crafty

   Synonyms: vafer, doctus, instructus, gnārus, perītus

   Antonyms: ineptus, rudis, inexpertus, imperītus, iners, incapāx, hospes, ignārus

3. (Medieval Latin, Ecclesiastical Latin) discreet
   • c. 347 CE – 420 CE, Hieronymus, Vulgate Proverbs.14.8:

     Sapientia callidī est intellegere viam suam: et inprūdentiā stultōrum errāns.

     The wisdom of a discreet man is to understand his way: and the imprudence of fools erreth. (Douay-Rheims trans., Challoner rev.: 1752 CE)

First/second-declension adjective.

• callidē
• calliditas
• callidulus

• Italian: callido
• Portuguese: cálido
• →? Welsh: call

• calidus

• “callidus”, in Charlton T. Lewis and Charles Short (1879), A Latin Dictionary, Oxford: Clarendon Press
• “callidus”, in Charlton T. Lewis (1891), An Elementary Latin Dictionary, New York: Harper & Brothers
• “callidus”, in Gaffiot, Félix (1934), Dictionnaire illustré latin-français, Hachette.