What ethnicity is the last name Teehan?

Its from Ireland, mostly now in kilkenny, kerry, Cork, Roscommon and Dublin, it is said to have origins in nottingham england where it came from a name like Tee who were possibly old celtic or saxon chieftains, after one of the several invasions of Britain they fled England and ended up in Ireland, possibly nearly 700-1000 years ago, the gaelic name for Teehan is OTiocahain (Oh-Te-Ah-Cawn) funnily enough similar to an Irish Word for fugitive.......................... D Teehan Meath Ireland