The placename is Welsh, meaning "bracken nook".[1] The area is largely Welsh-speaking. The parish appeared on a 1578 parish map of Pembrokeshire as Kilryden.[2]
West Cilrhedyn
The parish of West Cilrhedyn (Pembrokeshire) is now part of the community of Clydau. It had an area of 887 Ha, and consisted entirely of scattered farms. Its census populations were: 215 (1801): 257 (1851): 190 (1901): 127 (1951): 105 (1981). The percentage Welsh speakers was 100 (1891); 97 (1931); 94 (1971).