Muses (sacred poetry) is often seen with a pensive expression; Terpsichore (choral dance and song) is often seen dancing and carrying a lyre; Thalia (comedy) is often seen with a comic mask; and Urania (astronomy) carries a pair of compasses and the celestial globe. Greek "mousa" is a common noun as well as a type of goddess: it literally means "art" or "poetry". According to Pindar, to "carry a "mousa"" is "to excel in the arts". The word derives from the Indo-European root "men-", which is also the source of Greek "Mnemosyne" and "mania", English "mind", "mental" and "monitor", Sanskrit "mantra"
Muses associated with springs or with fountains. The Muses themselves were sometimes called Aganippids because of their association with a fountain called Aganippe. Other fountains, Hippocrene and Pirene, were also important locations associated with the Muses. Some sources occasionally referred to the Muses as "Corycides" (or "Corycian nymphs") after a cave on Mount Parnassos, called the Corycian Cave. Pausanias referred to the Muses by the surnames "Ardalides" or "Ardaliotides", because of a sanctuary to them at Troezen said to have been built by the mythical Ardalus. The Muses were venerated especially in Boeotia, in the Valley of the Muses near Helicon,