The Collaborative International Dictionary
To climb Parnassus
Parnassus \Par*nas"sus\, n. [L., fr. Gr. ?.] (Anc. Geog. & Gr. Myth.) A mountain in Greece, sacred to Apollo and the Muses, and famous for a temple of Apollo and for the Castalian spring.
Grass of Parnassus. (Bot.) See under Grass, and Parnassia.
To climb Parnassus, to write poetry. [Colloq.]