[Fou.cault pendulum] n [J.B.L. Foucault] (1931): a freely swinging pendulum that consists of a heavy weight hung by a long wire and that swings in a constant direction which appears to change showing that the earth rotates
FOUCAULT PENDULUM
Meaning of FOUCAULT PENDULUM in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012