certus

From Proto-Italic *kritos, the original perfect passive participle of *krinō (Latin cernō). Due to the shift in meaning, it was replaced in the verbal paradigm by crētus.

• (Classical Latin) IPA^(key):
• (modern Italianate Ecclesiastical) IPA^(key):

certus (feminine certa, neuter certum, comparative certior, superlative certissimus, adverb certē or certō); first/second-declension adjective

1. certain
   • 161 BCE, Publius Terentius Afer, Eunuchus 1.59–63:

     In amōre, haec omnia īnsunt vitia: iniūriae,
     suspīciōnēs, inimīcitiae, indūtiae,
     bellum, pāx rūrsum: incerta haec sī tū postulēs
     ratiōne certa facere, nihilō plūs agās
     quam sī dēs operam ut cum ratiōne īnsāniās.

     In love, all these flaws are present: wrongs, suspicions, enmities, truces, war, peace again: if you should desire to make these uncertain certain by reasoning, you would accomplish no more than if you made some effort — by way of reason — to become insane.

2. fixed, settled, firm
3. resolved, determined

   Synonyms: prōmptus, indubius, fixus

   Antonyms: incertus, dubius, suspensus, vagus, anceps

   certum est mihi ― it is my decision to..., I am resolved to..., I mean...

4. sure

First/second-declension adjective.

• “certus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “certus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• "certus", 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)
• certus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• Carl Meißner, Henry William Auden (1894) Latin Phrase-Book‎, London: Macmillan and Co.
  • the fixed stars: sidera certis locis infixa
    
  • this much is certain: hoc (not tantum) certum est
    
  • I am quite certain on the point: mihi exploratum est, exploratum (certum) habeo
    
  • I am determined: certum (mihi) est
    
  • I am firmly resolved: certum deliberatumque est
    
  • to impose fixed limitations: fines certos terminosque constituere
    
  • (ambiguous) I know for a fact: certo (certe) scio (Arch. 12. 32)
    
  • (ambiguous) this much I can vouch for: illud pro certo affirmare licet
    
  • (ambiguous) to be based on a sound principle: a certa ratione proficisci
    
• certus in Ramminger, Johann (2016 July 16 (last accessed)) Neulateinische Wortliste: Ein Wörterbuch des Lateinischen von Petrarca bis 1700‎, pre-publication website, 2005-2016