Son of corradh' (spear); a rare surname. in co. leitrim, it seems to have been a variant of mac corraidhín, which see, (Sloinnte Gaedheal is Gall )
Descendant of corra' (spear); a variant of Ó carra (which see); a rather common ulster surname. see Ó corraidh, which is also a variant, (Sloinnte Gaedheal is Gall )
Sources:
Sloinnte Gaedheal is Gall An Sloinnteoir Gaeilge agus an tAinmneoir