absence of the gods from their shrines in October
Shinto term referring to the belief that in the tenth month of the lunar calendar (now roughly October), the gods leave their local shrines and gather at Izumo Taisha. The phrase is often used in explanations of the month's alternative name, 神無月 (かんなづき).
The tenth month of the old calendar is called 'the gods' absence,' when all the gods of Japan are said to gather at Izumo Taisha.
Compound of 神 (かみ, 'god') + の (possessive particle) + 留守 (るす, 'absence'). The expression is rooted in Shinto folk belief.