This is a rare Irish surname. Recorded as Cloonan, Clunan, and associated with the Cloney, Clooney and Clowney nameholders, it is a name which is said to originate almost exclusively from County Galway. It is unclear how many name holders exist, but it could be as few as one hundred world wide, which makes it rare indeed. This is perhaps not entirely surprising as the medieval origination is from the Olde Gaelic word "cluana" through the surname O' Chuanaigh. This means literally the male descendant of the rogue! Who the "rogue" was is unclear, but like the vast majority of Irish clan surnames, it almost certainly originates from a nickname for the original chief of the clan perhaps seven hundred or more years ago, Given the robost humour of those medieval times, the chief probably regarded being called a rogue as some sort of badge of honour, which is why it was never changed. In any case whilst the translation of this surname may seem robust to modern ears, then so would the translation of Kennedy. This is "ugly head," and that of Dordan for instance, pygmy! It is unclear when the surname was first recorded as sadly most Irish records were lost in 1922 when the Public Records Office in Dublin was burnt down by the IRA. We do know that in 1846 one Hugh Cloonan was recorded in Liverpool, but he is believed to have emigrated to New York that year.