Ailsa f
Scottish: modern name derived from that of Ailsa Craig, a high rocky islet in the Clyde estuary off the Ayrshire coast, near the traditional estates of the Scottish Kennedys. Its name is derived from Old Norse Alfsigesey ‘island of Alfsigr’, a personal name composed of the elements alf elf, supernatural being + sigi victory. Adoption as a given name probably represents an Anglicized form of EALASAID (SEE Ealasaid). Ailsa Craig is known in Gaelic as Allasa, or popularly Creag Ealasaid.
First names dictionary. 2012.