It’s best not to delve too deeply into the Greek myths behind this word, which feature hermaphroditism, nocturnal emissions and castration. Merely a story of everyday life on Mounts Olympus and Parnassus.
The principal figure is Cybele, goddess of fertility and mistress of wild nature, who had a huge and jealous love for a young man named Attis. The legend was created by the ancient Phrygians, but was taken over by the Greeks (who identified her with Rhea, mother of the gods), and later by the Romans. Cybele was often pictured in a chariot drawn by lions and was worshipped by nine armed and crested men called Korybantes in Greek and Corybantes in Latin. They performed noisy, extravagant, orgiastic dances to the sounds of drums and other instruments.
Why, you have made her [Rhea] quite mad: she harnesses those lions of hers, and drives about all over Ida with the Corybantes, who are as mad as herself, shrieking high and low for Attis; and there they are, slashing their arms with swords, rushing about over the hills, like wild things, with dishevelled hair, blowing horns, beating drums, clashing cymbals; all Ida is one mad tumult.
Nigrinus, by Lucian of Samosata, 1st century AD.
In the seventeenth century, English gained corybantic to describe any unrestrained dancing and music making. In 1890, Thomas Henry Huxley wrote in the Times about “That form of somewhat corybantic Christianity of which the soldiers of the Salvation Army are the militant missionaries.”
A famous example appears in that extraordinary literary collaboration between Mehitabel the alley cat and Archy the cockroach:
cage me and i d go frantic
my life is so romantic
capricious and corybantic
and i m toujours gai toujours gai
Archy and Mehitabel, by Don Marquis, 1927. Archy does the typing but can't manage the shift and character keys at the same time, so everything is in lower case. He can’t do punctuation either.
A more recent example, from the literature of fantasy:
She taught him the courtly manners of the elf lords, and also the corybantic measures they trod when they were out in the open, barefoot in dew and drunk with moonlight.
The Broken Sword, by Poul Anderson, 1954.