The place name is fairly common in England, and is Old English meaning "cold cottage". This refers to a resting place for travellers or other strangers on the road. In this case the road in question is the ancient Watling Street that passes straight through the hamlet.
The place name was once used elsewhere in Buckinghamshire in the ancient village adjacant to Bedgrove, and is in use today as the name of an estate in Milton Keynes.