Glashagarriff is an anglicised version of the Irish Glaise Gharbh (meaning 'rough stream').

[3] The Ordnance Survey name book of c. 1840 gives various versions such as 'Clashgorrave', 'Closhagorrave', 'Closhagorriff' and 'Closhagorriv', and describes the river as rising out of the bogs of Doneens and Lyroe, flowing between the parishes of Aghinagh, Aghabollogue and Magourney, and falling into the River Lee to the south.

[5] An Irish Tourist Association survey of 1944 refers to the Glashagarriff river as having brown trout and freshwater eels, but no salmon angling, nor permit for trout fishing required.

At Cork Spring Assizes in 1807, a presentment was approved in favour of Richard Townsend and Cornelius Molony to repair 'Gassagariff bridge, between Cork and Macromp' for the amount of £10 9s 4d.

[7] At Cork Spring Assizes in March 1828, an application for a presentment was approved for the amount of £71 8s 8d, in favour of Charles Colthurst, John Bowen, John Haly and William Haly 'to widen Glashagorrive bridge on the road from Cork to Macroom.