Dickson
Dickson—In the district of Ballymoney and surrounding parts, in North Antrim, the surnames Deehan and Deighan have been anglicised Dickson (O'Díochon). Dickson itself is a South-East of Scotland name, having its origin in the English Pale of that country.
Alphabetical Index of Anglicised Surnames in Ireland
See also Woulfe’s Irish Names and Surnames
… and O'Hart's Irish Pedigrees