Dictionary Entry

Gur go mbeadh na hamhráin a chum ceathrú ann gurb é an focal traein a úsáideann sé gurb shin é an áit a bhfuil sé le fáil ins na cáipéisí mar a déarfá agus dhá réir sin is is is focal a théanns siar píosa maith.

So that the songs he composed a quarter of would have the word "train" that he uses, that is where it is to be found in the documents, as you might say, and according to that, it is a word that goes back quite a bit.