Webster's Revised Unabridged Dictionary · 1913

Parnassus

Parnassus , noun

[Latin, from Greek {not transcribed}.]

(Anc. Geography & Greek Mythology) A mountain in Greece, sacred to Apollo and the Muses, and famous for a temple of Apollo and for the Castalian spring.
Collocations (2)
Grass of Parnassus (Botany) , See under Grass, and Parnassia.
To climb Parnassus , to write poetry. [Colloquial]