early 15c., from Lowland Scottish, from Gaelic bealltainn "might 1," essential Celtic spiritual rite establishing the start of summer, most likely virtually "blazing fire," from PIE root *bhel- (1) "to shine, flash, burn" (see bleach (v.)) + Old Irish ten "fire," from PIE *tepnos, linked to Latin tepidus "warm." But this derivation associated with second element is hotly disputed by some on philological grounds, and fires had been equally important in the various other Celtic holidays. The rubbish about Baal, Bel, Belus imported to the word through the Old Testament and traditional antiquity, is away from range of clinical etymology. [OED] Also called "Old May-day," because after the 1752 diary reform it stayed reckoned in accordance with traditional style; it had been one of the quarter-days of ancient Scotland.
The first day's May (Old Style).
- A festival of heathen Celts on first-day of might, in the observance that great bonfires had been kindled. It nonetheless exists in a customized type in some elements of Scotland and Ireland.
(n.) The initial day of might (traditional style).
- (n.) A festival regarding the heathen Celts from the first-day of might, within the observance which great bonfires had been kindled. It still exists in a modified form in some parts of Scotland and Ireland.
Its name is supposed to point to the time when Beltane rites were observed on its summit.