LATIN DICTIONARYLexicon Latīnum
noun · masculinesecond declension

triāriī

triāriī m pl (genitive triāriōrum)
Classical[triˈaː.ri.iː]

Meaning

  1. pluralplural onlythe third and last line in the Roman army (after, respectively, the prī̆ncipēs and the hastātī)
    Ab Romanis nec opus intermissum—triarii erant, qui muniebant—et ab hastatis principibusque, qui pro munitoribus intenti armatique steterunt, proelium initum.The works were not set aside by the Romans—triarii where there to fend off the enemy—and a fight broke out led by the hastati and principes, eager and fully-equiped, who had been placed before the workers.27 BCE – 25 BCE, Titus Livius, Ab urbe condita 7.23

Declension

declension
formsingularplural
nominative—triāriī
genitive—triāriōrum
dative—triāriīs
accusative—triāriōs
ablative—triāriīs
vocative—triāriī

Phrases from Meissner's Latin Phrase-Book

res ad triarios redit (Liv. 8. 8)
the triarii must now fight (proverbially = we are reduced to extremities).

trĭārĭi, ōrum, m. tres,
I. a class of Roman soldiers who formed the third rank from the front, the triarii, Varr. L. L. 5, § 89 Müll.: etiamsi te sors inter triarios posuerit, Sen. Tranq. 3, 10; Liv. 22, 5, 7: a primā acie ad triarios sensim referrebantur, id. 8, 8, 11; 8, 10, 6; cf. Becker, Antiq. 3, pt. 2, p. 249 sq.

Origins

  1. Proto-Indo-European*tréyes
  2. Proto-Italic*trejes
  3. Proto-Italic*trēs
  4. Latintriāriī

Proto-Indo-European *-yósder. Proto-Italic *-āzios Latin -āriusnom. Latin -āriī Latin triāriī From tri- (“three”) + -āriī (plural of -ārius, forming agent nouns).

Quick answers

What does triāriī mean in Latin?
triāriī, a noun, means “the third and last line in the Roman army (after, respectively, the prī̆ncipēs and the hastātī)”.
What is the genitive of triāriī?
The genitive singular is triāriōrum. triāriī is masculine, second declension.
How do you pronounce triāriī?
In classical Latin, [triˈaː.ri.iː].
Where does triāriī come from?
Proto-Indo-European *tréyes → Proto-Italic *trejes → Proto-Italic *trēs → Latin triāriī.