Don't fully trust what you find in that website, it is very likely to be wrong.
Coming to think of it, Teague is the Anglisized form of Tadhg. Tadhg is prn. "tieg", it sounds almost like "teeg". Merriment, a regular poster, expert on Welsh names, gave me this information a while a go. Too bad she isn't around to cofirm it for you, at the moment.
Hope this helps,
Magia
Ps.: Does anyone know where Merriment is?