The townland name is an anglicisation of the Gaelic placename Rath Caolain which is usually given as 'Keelan's Fort' but a more likely explanation is Rath Caolán, meaning the Fort of the Little Narrow Place, as the townland is squeezed between the Shannon-Erne Waterway on the east side and Slieve Rushen on the west side. The oldest surviving mention of the name is in the 1609 Ulster Plantation map where it is spelled Rakellan. A 1610 grant spells it as Rathkeylane. A 1630 Inquisition spells it as Rathkillan. The 1652 Commonwealth Survey spells the name as Rakeelane. The 1663 Hearth Money Rolls spell it as Rakelane. A 1666 grant spells it as Rathkylan. The 1790 Cavan Carvaghs list spells the name as Rakillan.