den / den/ • n. a wild animal's lair or habitation. ∎ inf. a small, comfortable room in a house where a person can pursue an activity in private. ∎ a place where people meet in secret, typically to engage in some illicit activity. ∎ a small subdivision of a Cub Scout pack.• v. (denned, den·ning) [intr.] (of a wild animal) live in or retreat to a den.
a wild beasts’ lair, hence, the beasts themselves.
Examples: den of foxes, 1300; of lemur; of lions, 1380; of robbers, 1860; of snakes; of thieves, 1719; of tigers, 1400; of vice.