What's in a name? Tiermanagh, Co Limerick

Hello, I was wondering if someone might confirm that Tiermanagh (located on the map as between Derk and Treanmannagh Townlands, Co Limerick) is actually a village name. 

My ancestors John and Mary Fleming, came from Treanmannagh Townland (Civil Parish Tuoghcluggin) in the mid-1800s and my Great great Uncle called his home in Australia "Tearmanna".   

I can't find any mention of Tiermanagh on the old ordnance maps yet, on modern maps, it appears as a spot between the two townlands and as the name of a road.  

If it is a village (of which I can find no evidence) how far would it have extended?

I guess this is really just a local knowledge question but I am hoping someone out there might be able to help me to understand if my family lived in Tiermanna or if it was a nearby town.  Thank you very much for any advice. 

Mary