Sources

Crosenecon 1203 x 1207 RRS ii no. 462

Hill of Cossinkon c. 1591 Pont map 35

Crosin Con Roy Lowlands [twice, for hill and settlement]

Crossin Con 1807 Arrowsmith

“It [Corsencon] is for cros na con, ‘the hound’s crossing,’ with reference probably to the crossing over the hill of Corsancone, for there is no evidence for a cross having stood at the place. Cù, a hound, is here feminine, as it was and is in Irish, though masculine now in Scottish Gaelic” Watson 1926 198-9

There is some online discussion of this name as being from various other derivations, but all hang their arguments on aberrant early forms, whilst the proposed derivation is clearly the correct one looking across all the early forms. A plural form would be preferable to Watson’s singular form