Definition of "Castle"

(countable) A surname transferred from the common noun referring to someone who lived in or worked in a castle  examples

(UK, rail transport) Castle class, a class of steam locomotives used on the GWR  examples

(UK, Durham University slang) University College, Durham, a constituent college located in Durham Castle

A hamlet in Bowerchalke parish, south-west Wiltshire, England (OS grid ref SU0122).  examples

A community (without a council) in Cardiff, Wales; it includes Cardiff Castle.  examples

A community (without a council) in Swansea, Wales; it includes Swansea Castle.  examples

A town in Okfuskee County, Oklahoma, United States, derived from the surname.  examples