Definition of royal oak:
(n) :
An oak tree in which King Charles II hid, and a popular name for public houses in the United Kingdom, past and present.
(n) :
A city in Oakland County, Michigan, United States, named after the English oak tree.
(n) :
A charter township in Oakland County, Michigan, the smallest in the state.
(n) :
An underground station (above ground) in the City of Westminster borough, Greater London, originally named after a pub (OS grid ref TQ2581).
(n) :
A hamlet in Heighington parish, Darlington borough, County Durham, England (OS grid ref NZ2023).
(n) :
A settlement in Bickerstaffe parish, West Lancashire district, Lancashire, England (OS grid ref SD4103).