Where’s the one place that bears go to hibernate and you go to watch the big game? It’s the den, a secluded room or shelter.
Den is an Old English word meaning “shelter for a wild animal.” While we still use it in this sense, the word has taken on some additional meanings. For example, den can refer to a room that's used primarily for relaxing, watching television, and socializing with friends. (If your friends tend to act wild at times, then perhaps this definition isn’t so far off from the original one.) Den can also mean "a hideout for criminals."