What an interesting question and only ringing the faintest of bells from Dougal's marble playing days long ago. It’s a word from the north-east of Scotland – though it’s also in dictionaries of Shetland words – and means a hole in the ground – a target for the marbles. Kype or kypie (presumably a wee holey!) is linked to Old English cype and Low German kipe meaning a basket – hence anything of a concave shape.