LATIN DICTIONARYLexicon Latīnum
noun · femininethird declension

arx

arx f (genitive arcis)
Classical[ˈarks]Ecclesiastical[ˈarks]
№ 638 of the 1,000 commonest wordsMille Verba core vocabulary

Meaning

  1. femininestronghold, castle, citadel, fortress, acropolis
    ... Trōiaque, nunc stārēs, Priamīque arx alta, manērēs.... and Troy, you would now be standing, and Priam's mighty citadel still endure.Vergil, Aeneid, 2.56
  2. femininefigurativelydefence, protection, refuge, bulwark
  3. femininetyranny (with arx as the abode of tyrants)
  4. femininemetonymicallyheight, summit, pinnacle, top, peak (since castles were often built on heights)
    venit in hoc illa fulmen ab arce caput.It fell on this head [of mine], a thunderbolt from that height. (Jupiter (mythology) hurled thunderbolts from heaven, whereas the Emperor Augustus, living atop the Palatine Hill, had sentenced Ovid to exile.)8 CE – 12 CE, Ovidius, Tristia 1.72

Latīnē defined in Latin in our graded readers

locus altus et mūnītus urbis; caput urbis.
arx arcis f — in Mille Verba, Urbs et Aedificia

Declension

declension
formsingularplural
nominativearxarcēs
genitivearcisarcium
dativearcīarcibus
accusativearcemarcēs
arcīs
ablativearcearcibus
vocativearxarcēs

arx, arcis, f. arx ab arcendo, quod is locus munitissimus rubis, a quo facillime possit hostis prohiberi, Varr. L. L. 5, § 151 Müll; cf. Serv. ad Verg. A. 1, 20; Isid. Orig. 15, 2, 32; Doed. Syn. IV. p. 428; v. arceo,
I. a stronghold, castle, citadel, fortress, ἀκρόπολις; in Rome, the Capitolium.
I. A.. Lit.: arce et urbe orba sum, Enn. ap. Cic. Tusc. 3, 19, 44 (Trag. v. 114 Müll.): optumates, Corinthum quae arcem altam habetis, id. ap. ejusd. Fam. 7, 6: edicite per urbem ut omnes qui arcem astuque accolunt, cives, etc.; Att. ap. Non. p. 357, 14: Illa autem in arcem [hinc] abiit, Plaut. Bacch. 4, 8, 59; so id. Ps. 4, 6, 2: In arcem transcurso opus est, Ter. Hec. 3, 4, 17: Condere coeperunt urbīs arcemque locare, Lucr. 5, 1107: arcis servator, candidus anser, id. 4, 683: munire arcem, Cic. Pis. 34 fin.: cum Tarento amisso arcem tamen Livius retinuisset, id. de Or. 2, 67, 273: arx intra moenia in immanem altitudinem edita; Liv. 45, 28: arx Sion, Vulg. 2 Reg. 5, 7: arx Jerusalem, ib. 1 Macc. 13, 49: Romana, Liv. 1, 12: Capitolina, id. 6, 20; cf. id. 3, 18: Sabinus arcem Capitolii insedit mixto milite, Tac. H. 3, 69; Suet. Claud. 44 et saep. As the place on which auguries were received (cf. auguraculum): ut cum in arce augurium augures acturi essent, Cic. Off. 3, 16, 66; so Liv. 1, 18 and 24.—Hence,
B. Trop., defence, prolection, refuge, bulwark, etc.: Castoris templum fuit te consule arx civium perditorum, receptaculum veterum Catilinae militum, castellum forensis latrocinii, Cic. Pis. 5, 11: haec urbs, lux orbis terrarum atque arx omnium gentium, id. Cat. 4, 6; cf. id. Agr. 1, 6, 18: Africa arx omnium provinciarum, id. Lig. 7, 22: Stoicorum, id. Div. 1, 6, 10: arx finitimorum, Campani, Liv. 7, 29; 37, 18: tribunicium auxilium et provocationem, duas arces libertatis tuendae, id. 3, 45: arx ad aliquid faciendum, id. 28, 3: eam urbem pro arce habiturus Philippus adversus Graeciae civitates, id. 33, 14; Flor. 3, 6, 5: quasi arx aeternae dominationis, Tac. A. 14, 31.—
C. As the abode of tyrants, a poet. designation of tyranny (cf. Ascon. ad Cic. Div. in Caecil. 5), Claud. IV. Cons. Hon. 293 Heins.: cupidi arcium, Sen. Thyest. 342; cf. id. Contr. 4, 27: non dum attigit arcem, Juris et humani culmen, Luc. 7, 593 Corte; cf. id. 8, 490, and 4, 800; Tert. Apol. 4.—
D. Prov.: arcem facere e cloacā, to make a mountain of a mole-hill, Cic. Planc. 40.—
II. Since castles were generally on a height, meton., a height, summit, pinnacle, top, peak (usu. poet. and in Aug. and postAug. prose), lit. and trop.
A. Lit.: summā locum sibi legit in arce, upon the extreme height, Ov. M. 1, 27; cf. id. ib. 12, 43. —So,
2. In partic.
a. Of mountains: Parnasi constitit arce, Ov. M. 1, 467: arce loci summā, id. ib. 11, 393: Rhipaeae arces, Verg. G. 1, 240: flērunt Rhodopeïae arces, id. ib. 4, 461: septemque unā sibi muro circumdedit arces, id. ib. 2, 535: primus inexpertas adiit Tirynthius arces, i. e. Alpes, Sil. 3, 496; cf. Drak. ad id. 15, 305; Val. Fl. 3, 565: impositum arce sublimi oppidum cernimus, Petr. 116; cf. id. 123, 205, and 209.—
b. Of houses built on an eminence, Petr. 121, 107, and 293.—
c. Of the citadel of heaven: quae pater ut summā vidit Saturnius arce, Ov. M. 1, 163: summam petit arduus arcem, id. ib. 2, 306: sideream mundi qui temperat arcem, id. Am. 3, 10, 21.—
d. Of the heavens themselves: aetheriae arces, Ov. Tr. 5, 3, 19: arces igneae, Hor. C. 3, 3, 10: caeli quibus adnuis arcem, Verg. A. 1, 250; cf. id. ib. 1, 259.—
e. Of temples erected on an eminence: dexterā sacras jaculatus arces, Hor. C. 1, 2, 3.—
f. Of the head: arx corporis, Sen. Oedip. 185; Claud. IV. Cons. Hon. 235.—
B. Trop., height, head, summit, etc. (rare): celsā mentis ab arce, Stat. S. 2, 2, 131: summae laudum arces, Sil. 13, 771; Sid. Carm. 2, 173: ubi Hannibal sit, ibi caput atque arcem totius belli esse, head and front, Liv. 28, 42: arx eloquentiae, Tac. Or. 10.

Origins

Perhaps from Proto-Italic *arks, from Proto-Indo-European *h₂érk-s, from the root *h₂erk- (“to protect, guard, hold, lock”). De Vaan suggests that the root noun may have been formed innovatively within Proto-Italic itself or perhaps at an even later date. Cognates include Latin arca (“chest, box”), arceō (“to defend”), arcānus (“hidden, secret”), arcera (“covered carriage for sick people”), Old Armenian արգել (argel, “obstacle”) and Ancient Greek ἀρκέω (arkéō, “to ward off, fend off”), Persian ارگ (arg, “citadel”)

In the Academy Smith's classical dictionaries

Quick answers

What does arx mean in Latin?
arx, a noun, means “stronghold, castle, citadel, fortress, acropolis; height, summit, pinnacle, top, peak (since castles were often built on heights)”.
What is the genitive of arx?
The genitive singular is arcis. arx is feminine, third declension.
How do you pronounce arx?
In classical Latin, [ˈarks]; in ecclesiastical (church) Latin, [ˈarks].