1. (southern) reduced Anglicized form of Gaelic Ó Foghladha ‘descendant of Foghlaidh’, a byname meaning ‘pirate’, ‘marauder’.
2. (northern) Anglicized form of Gaelic Mac Searraigh (see > McSharry), chosen because of its phonetic approximation to English foal.
>> Irish: Anglicized form of Gaelic Mac Searraigh (see > McSherry).
>> Irish (southern Ulster): Anglicized form of Gaelic Mac Searraigh ‘son of Searrach’, a personal name based on searrach ‘foal’. It is sometimes further Anglicized as Foley
(Dictionary of American Family Names, Oxford University Press)
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