A kettle hole is a depression in a glacial outwash plain formed by the melting of a detached block of ice buried in the sediment. These features often become ponds or small lakes. Kettle holes are important in understanding glacial processes and post-glacial landscapes.
Source Johnson, W. H., & Clayton, L. (2003). “Formation of Kettles by Subglacial Meltwater.” Geological Society of America Bulletin, 115(5), 645-654.