Definition of "Anglesey"

An island and traditional county at the northwestern extremity of north Wales. It is separated from Caernarfonshire on the mainland by a narrow stretch of water called the Menai Strait. The county was merged into Gwynedd in 1974.  examples

A unitary authority in Wales, Isle of Anglesey County Council, created in 1996 when it was separated from Gwynedd.  examples

A marquisate in the peerage of the United Kingdom.  examples