The term 'fox hole' is a combination of three words: 'LAIR, ' 'EARTH, ' and 'DEN.' A fox's LAIR is a small shelter or DEN that it uses as a home. EARTH is the material that is used to build the fox's DEN, which is usually dug into the ground. Finally, a DEN is a small shelter or hiding place, often dug into the ground, that animals use for protection and safety. Therefore, a fox hole is a small shelter or DEN that is dug into the EARTH and used by a fox for protection and safety.