Definition of patent theatre in US English:

patent theatre

(US patent theater)

noun

historical
  • Any of several theatres established by Royal Patent between the 17th and 19th centuries; specifically (in London) the theatres of Covent Garden and Drury Lane, whose Patents were granted by Charles II in 1662.

Origin

Mid 19th century; earliest use found in Charles Dickens (1812–1870), novelist.