the.com/rain dance

means A ceremonial dance performed, often by Indigenous peoples, to summon or encourage rainfall, and now also used loosely for any superstitious ritual meant to force the weather's hand.

from The term describes rituals found across many cultures worldwide — Hopi and other Pueblo peoples, various African societies, and others all developed rain-calling dances independently, since drought is a universal problem and rhythm-plus-ritual a universal response to powerlessness. The English phrase itself is a straightforward 20th-century compound, popularized by Western observers describing these ceremonies — though it flattens enormously varied sacred traditions into one generic label. Its casual modern use ('I did my rain dance before the exam') comes from the idea taking hold in pop culture as shorthand for any hopeful, slightly absurd ritual performed when you have no real control over the outcome.