LATIN DICTIONARYLexicon Latīnum
proper noun · masculinesecond declension

Mārsī1

Mārsī m pl (genitive Mārsōrum)
Classical[ˈmaːr.siː]Ecclesiastical[ˈmar.si]

Meaning

  1. An ancient tribe who inhabited a region in central Italy, around the basin of the lake Fucinus.
  2. Medieval Latinenchanters, sorcerers, magicians
    marsi, magi dryas, (dry)lice inguleres (l. -as) Hpt. Gl. 510, 25; An. Ox. 4476; marsi, drias 2, 338.1922 (c. 700), Richard Jente, Die mythologischen Ausdrücke im altenglischen Wortschatz, Heidelberg: C. Winter, page 285:

Declension

declension
formsingularplural
nominative—Mārsī
genitive—Mārsōrum
dative—Mārsīs
accusative—Mārsōs
ablative—Mārsīs
vocative—Mārsī

Marsi, ōrum, m.
I. A people in Latium, on the Lacus Fucinus, celebrated as wizards and snake-charmers; in the Social War the most zealous enemies of the Romans, Plin. 7, 2, 2, § 15; 3, 12, 17, § 106; Caes. B. C. 1, 15; Liv. 8, 6; 9, 41 sq.; 26, 11; Flor. 3, 18, § 6; § 13 et saep.—Sing. collect., Cic. Div. 2, 33, 70.—
B. Hence,
1. Marsus, a, um, adj., of or belonging to the Marsi, Marsian: augur, Auct. ap. Cic. Div. 1, 58, 132; Cic. ib. 2, 33, 70: manus, Enn. ap. Charis. p. 251 P. (Ann. v. 280 Vahl.): ager, Luc. 9, 790: montes, Verg. A. 7, 758; Col. 6, 5, 3: nives, Stat. S. 1, 5, 26: aper, Hor. C. 1, 1, 28: cellae (for the wine; v. Marsicus), Mart. 14, 116: centuriones, Caes. B. C. 2, 27: nenia, incantations, Hor. Epod. 17, 29; Ov. A. A. 2, 102: duellum, Hor. C. 3, 14, 18: senex, Juv. 14, 180.—
2. Marsĭcus, a, um, adj., Marsian, Marsic: bellum, Cic. Agr. 2, 33, 90; id. Div. 1, 44, 99; 2, 27, 59: pubes, Sil. 8, 496: vinum, Mart. 13, 121.—
II. A people of Germany, between the Rhine, Lippe, and Ems, Tac. G. 2; id. A. 1, 50; 56; 2, 25; id. H. 3, 59.

In the Academy Smith's classical dictionaries

proper noun · masculinesecond declension
Marsī2
Marsī m pl (genitive Marsōrum)
Classical[ˈmar.siː]Ecclesiastical[ˈmar.si]

Meaning

  1. A small Germanic tribe settled between the Rhine, Ruhr and Lippe rivers in northwest Germany.

Declension

declension
formsingularplural
nominative—Marsī
genitive—Marsōrum
dative—Marsīs
accusative—Marsōs
ablative—Marsīs
vocative—Marsī

Origins

From Proto-Germanic *marsiz.

In the Academy Smith's classical dictionaries

Quick answers

What does Mārsī mean in Latin?
Mārsī, a proper noun, means “An ancient tribe who inhabited a region in central Italy, around the basin of the lake Fucinus.; enchanters, sorcerers, magicians”.
What is the genitive of Mārsī?
The genitive singular is Mārsōrum. Mārsī is masculine, second declension.
How do you pronounce Mārsī?
In classical Latin, [ˈmaːr.siː]; in ecclesiastical (church) Latin, [ˈmar.si].