|Author||Rev Patrick Woulfe|
|Source||Irish Names and Surnames|
Mac ALASTRUIM—V—M'Alastrom, M'Alastrum, M'Ellistrom, MacElistrum, MacElestrim, MacEllistram, etc.; 'son of Alastrom' (a Gaelic form of Alexander); a variant of Mac Alastair, which see. This form of the surname is peculiar to Kerry, where the family has been settled for centuries.
Alphabetical Index to Irish Surnames