Beltane

Webster's Dictionary

(1): (n.) The first day of May (Old Style).

(2): (n.) A festival of the heathen Celts on the first day of May, in the observance of which great bonfires were kindled. It still exists in a modified form in some parts of Scotland and Ireland.

The Nuttall Encyclopedia

Or

n ancient Celtic festival connected with the sun-worship, observed about the 1st of May and the 1st of November, during which fires were kindled on the tops of hills, and various ceremonies gone through.