Lacus

The Latin word lacus means "opening, hole, pool, lake," and was also the word for a distribution point in the public water supply of ancient Rome. It can refer to:

Geography

 * Lucrinus Lacus, a lake in Campania
 * Albanus Lake, Lake Albano in Lazio, Italy
 * Alsietinus Lacus, the ancient name of a lake in Etruria today known as Lake Martignano
 * Lacus Curtius, a topographical feature in ancient Rome
 * Lacus Juturnae, a spring and man-made religious structure in ancient Rome

Extraterrestrial
Lacus may also refer to a lunar mare; see List of maria on the Moon:
 * Lacus Aestatis
 * Lacus Autumni
 * Lacus Bonitatis
 * Lacus Excellentiae
 * Lacus Felicitatis
 * Lacus Mortis
 * Lacus Solitudinis
 * Lacus Somniorum
 * Lacus Spei
 * Lacus Temporis

Lacus may refer to similar features on other celestial bodies:
 * Ontario Lacus on Titan, a moon of Saturn
 * Solis Lacus on Mars

Fictional characters

 * Lacus Clyne from Mobile Suit Gundam SEED and Mobile Suit Gundam SEED Destiny anime.

Associations

 * Linguistic Association of Canada and the United States