A contest in wizardry took place between two wizards of the Tuath dé Danann, named Cithnellach the druid and Conn the druid. Conn brought a great snow all round Connaught, so that from then till today the name Connacht clave to the province, that is, Cuinn snechta, the druid Conn’s snow.

(from ‘Cóir Anmann: Fitness of Names’)