Family name origins & meanings
- Scottish : local name from the city on the Clyde (first recorded in 1116 as Glasgu), or from either of two minor places with the same name in Aberdeenshire. The etymology of the place name is disputed; it is probably from Welsh glas ‘gray’, ‘green’, ‘blue’ + cau ‘hollows’.
- Scottish and Irish : altered form of Closkey, reduced and Anglicized form of Gaelic Mac Bhloscaidhe ‘son of Bloscadh’ (see McCloskey).
- Irish : variant of the English family name Glasscock, which was once common in County Kildare.