LATIN DICTIONARYLexicon Latīnum
suffixfirst/second-declension suffix

-ius1

-ius (feminine -ia, neuter -ium)
Classical[i.ʊs]Ecclesiastical[i.us]

Meaning

  1. morphemerelationalsuffixforming adjectives from nouns
    Near-synonyms: -eus, -īnus, -us, -icus
  2. morphemesuffixending of most Classical Latin 'nomina gentilicia' (family names or surnames, shared by the members of a gens)
  3. morphemesuffixsuffix forming patronymic cognomina
    Cōnstāns + -ius → Cōnstantius
  4. New Latinmorphemesuffixsuffix for Latinizing surnames

Origins

From Old Latin -ios, from Proto-Italic *-i(j)os, from Proto-Indo-European *-yós. Cognate with Ancient Greek -ῐος (-ĭos).

Descendants
  • Catalan-i
  • Italian-io
  • Portuguese-io
  • Spanish-io
suffix
-ius2
-ius
Classical[i.ʊs]Ecclesiastical[i.us]

Meaning

  1. morphemeforms comparative adverbs

Origins

Proto-Italic *-jōsinflu. Proto-Italic *-jos Latin -ius Inherited from Proto-Italic *-jos.

suffix
-ius3
-ius
Classical[i.ʊs]Ecclesiastical[i.us]

Meaning

  1. morphemethe regular genitive singular suffix for most pronouns
    quī: cuius
    hic: huius

Origins

From Proto-Italic *-osjos, itself from Proto-Indo-European *-ósyo (genitive case suffix) secondarily marked with the genitive *-s.

Quick answers

What does -ius mean in Latin?
-ius, a suffix, means “forming adjectives from nouns; ending of most Classical Latin 'nomina gentilicia' (family names or surnames, shared by the members of a gens); suffix forming patronymic cognomina”.
How do you pronounce -ius?
In classical Latin, [i.ʊs]; in ecclesiastical (church) Latin, [i.us].