The name MacDermot Roe means son of Dermot the Red. Red in Gaelic is rendered ruadh. In this case, the Roe refers to the color of Dermot's hair.

It is generally said that the Dermot Roe after whom the family took its name was Dermot Roe MacDermot who was buried at Boyle Abbey in 1341. However, his grandfather Dermot Dall was, also, known as Dermot Roe before he was blinded by Aedh, King of Connaught in 1266.

In ancient times, it was common for Irish to distinguish themselves from others with the same given name by adding an appellation or nickname. So, for example, there might be a Conor Og, Conor Don and Conor Roe. Og = young/junior. Donn=brown.

The use of appellations in given names continued after the adoption of surnames in the middle ages. This could lead to quite a long name when the person's ancestry was included. Take, for example, Thomas oge McHugh Duff (Dubh/Duff=black) McDermott Roe, fl. 1617.

While the use of appellations in given names was common, the use of appellations with surnames was not. Another example of use with a surname is that of the O'Conors of Connaught whose chief branch is O'Conor Don. In the O'Conor Don family, only the chief uses the Don in his name. In the MacDermots Roe, all descendants may use the Roe.

In Gaelic culture the name was properly rendered as two words, MacDermot Roe. However, in modern times the name evolved in many variations. These were largely developed to avoid alphabetical confusion where the Roe would be mistaken for the surname. Among the variations are McDermottroe, McDermott-Roe, MacDermot-Roe, and MacDermotRoe.

Copyright Biatach 2014