Definition of Act of Parliament clock in English:

Act of Parliament clock

noun

British
  • A large 18th-cent. wall clock typically having gold numerals on an uncovered black or green dial and usually displayed in an inn, tavern, or similar establishment.

    The name arose from the popular belief that such clocks were acquired by innkeepers in order to attract custom after Parliament passed an act in 1797 imposing a tax on clocks and watches.

Origin

Late 19th century; earliest use found in Frederick Britten (1843–1913).