What a coincidence! I am also trying to trace Tierneys of Clifford. My great great grandmother was Mary Tierney who married Aloysius Carton (their daughter Mary Ann married my great grandfather Frederick Goodburn).
I've been trying to work out the Tierney connections for ages. I know John Tierney (1818-1881) had at least 5 children: Mary (1843-96), Margaret (mar James Naughton 1865), Rose (mar Thomas Masterson 1865), Bridget (mar James Hague 1870) and Catherine (1851-1900), who all settled in Clifford.
What I can't figure out is their relation to your Peter Tierney. He's listed on the 1881 census as being from County Cavan, whereas the others are all apparently from Ballymaine, which unfortunately doesn't seem to exist! I was wondering if he was a son of John but I can't find out one way or another. They must have been relations of some kind.
Do you have any ideas about all of this? Do you know if your Tierneys were related to the Cartons/Goodburns of Clifford?
Best wishes for successful Tierney-hunting. Charlotte