LATIN DICTIONARYLexicon Latīnum
proper noun · masculinesecond declension

Petīlius

Petīlius m sg (genitive Petīliī or Petīlī)
Classical[pɛˈtiː.li.ʊs]Ecclesiastical[peˈtiː.li.us]

Meaning

  1. a Roman nomen gentile, gens or "family name" famously held by
  2. Quintus Petilius Cerialis, a Roman general

Declension

declension
formsingularplural
nominativePetīlius—
genitivePetīliī
Petīlī		—
dativePetīliō—
accusativePetīlium—
ablativePetīliō—
vocativePetīlī—

Pĕtīlĭus, a,
I. name of a Roman gens. —Hence,
A. Pĕtīlĭus, a, um, adj., of or belonging to a Petilius, Petilian: lex, Liv. 38, 55.—
B. Pĕtīlĭānus, a, um, adj., Petilian: regna, i. e. the villa of a certain Petilius, otherwise unknown, Mart. 12, 57, 19.

Origins

From petīlus (“thin, slim”) + -ius.

Quick answers

What does Petīlius mean in Latin?
Petīlius, a proper noun, means “a Roman nomen gentile, gens or "family name" famously held by”.
What is the genitive of Petīlius?
The genitive singular is Petīliī. Petīlius is masculine, second declension.
How do you pronounce Petīlius?
In classical Latin, [pɛˈtiː.li.ʊs]; in ecclesiastical (church) Latin, [peˈtiː.li.us].