The term 'deep hole' can be described by two crossword solutions: 'ABYSS' (5 letters) and 'PIT' (3 letters). An ABYSS is a deep, immeasurable space or cavity, often filled with water. It is usually found in the ocean and is so deep that it cannot be measured. A PIT, on the other hand, is a large, deep hole in the ground, usually created by excavation or natural erosion. It is typically used for mining, storage, or disposal of waste materials. Both terms refer to a deep hole, but an ABYSS is typically found in the ocean while a PIT is found on land.