Aidan (?e?d?n) n (Biography) Saint. died 651 ad, Irish missionary in Northumbria, who founded the monastery at Lindisfarne (635). Feast day: Aug 31Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014