-cus

From Proto-Italic *-kos, from Proto-Indo-European *-kos, *-ḱos. Cognate with Ancient Greek -κός (-kós), Proto-Germanic *-gaz, Sanskrit -शस (-śasa) and Proto-Slavic *-kъ.

PIE *-ko- on noun stems carried the meaning 'characteristic of, like, typical, pertaining to', and on adjectival stems it acted emphatically.

• (Classical Latin) IPA^(key): [ˈkʊs]
• (modern Italianate Ecclesiastical) IPA^(key): [ˈkus]

-cus (feminine -ca, neuter -cum); first/second-declension suffix

1. suffixed to nouns, forms adjectives

   juvenis + -cus → juvencus

   Mārs + -cus → Mār(t)cus

   ravis + -cus → raucus

This suffix survives in inherited forms and became productive through its derivations (cf. infra) by metanalysis.

First/second-declension adjective.

• -icus
  • -ticus
    • -āticus
• -īcus
  • -īcius

• “-cus” on page 478/2 of the Oxford Latin Dictionary (1st ed., 1968–82)