April 23, 2020 at 6:57 pm #46500
I think THIAR is an adjective, used with a noun
an tír thiar – the west country
an taobh thiar – the west side
Iarthar is a noun. – the West
Thiar is an adverb.
But it can be used like an adjective, just like “over there” in English: the house over there.