The term 'BEARS' LAIRS' is a reference to the DENS or shelters that bears use for hibernation and protection from predators. The crossword solution for this term is 'DENS', which is a four-letter word meaning a small, secluded room or cave used as a shelter or refuge. Bears typically build their DENS in hollowed out logs, caves, or burrows in the ground. These DENS provide a safe and secure environment for the bear to rest during the winter months.