Smoot or smout?

According to google, one of naturalist Robert Macfarlane's Words of the Day is smoot-hole (or smout-hole) a gap built into the base of a dry-stone wall to allow passage of hares, rabbits and other small animals - but not sheep - between fields and the fells.
But, google also says a smout hole is a rectangular opening at the base of a wall built to permit passage of sheep.
Also apparently known as a hogg hole, a lonky hole, or a sheep smouse.
Whatever, it gave me an excuse for a stop on an uphill bit of a run today.  The sun is shining on the Howgill Fells beyond.