Foyle comes from an English surname which seems to derive from French fouille meaning “excavation”, originating as a locational name for someone who lived near a pit or man-made hollow.
Foyle is also the name of a river in Ireland which seems to be derived from Feabhal, the name of the father of Bran mac Feabhail (Bran son of Febail), a figure from Irish mythology who embarks on a quest to the underworld, and a name I couldn’t find much of a meaning behind; though I’ve also the River Foyle listed as possibly meaning “lip of the estuary”.
Origin: Proto-Indo-European
Meaning: “excavation” as a English surname; as an Irish place-name it may be derived from Irish Feabhail, or possibly meaning “lip of the estuary”
Usage: English, Irish
Nicknames: Foy
Names Throughout the Ages 