Recorded as MacColum in Northern Ireland, Colam, Collum and Colum in County Longford in the Republic, this is an Irish surname. It derives from the pre 10th century Gaelic word 'colm' meaning a dove, and was probably a nickname when originally 'bestowed' for a man of peace or even a holy man, However given the robust humour of the medieval period, the complete reverse is possible. As an example Little John was not the smallest man in the band of outlaws lead by Robin Hood, he was the biggest. Indeed it can be said that almost anything is possible with 'names, particularly as with this one it seems to have crossed national borders. Itr is also possible that the name is a variant form of Collins which is recorded in Ireland as Colan and Cullane. Over the centuries as names have passed between both countires and different languages, many have undergone considerabvle transpositions, sometimes to the point of being barely recognizeable. This may well be one of them, indeed it could even be a form of Calhoun. The first acceptable proven recording is believed to be that of Sarah Collun who married Jonathn White at St Catherines church, Dublin, on January 21st 1708.