Significatio vocis arx | Babel Free

Definitiones

1. stronghold, castle, citadel, fortress, acropolis
   declension-3, feminine
2. defence, protection, refuge, bulwark
   declension-3, feminine, figuratively
3. tyranny (with arx as the abode of tyrants)
   declension-3, feminine
4. height, summit, pinnacle, top, peak (since castles were often built on heights)
   declension-3, feminine, metonymically

Aequivalentia

Exempla

“... Trōiaque, nunc stārēs, Priamīque arx alta, manērēs.”

... and Troy, you would now be standing, and Priam's mighty citadel still endure.

“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.)

Gradus CEFR