lion's den
Any dangerous or frightening place.
Mrs. Bowls cautioned her lodger against venturing into the lion's den, "wherein you will rue it, Miss B., mark my words, and as sure as my name is Bowls."
ADJ.
preferred
My preferred den is the cozy corner of the library where I study every afternoon.
VERB + DEN
became, chose, darts, entered, entering, gambling, know, party
He entered the den where the lion was sleeping peacefully on the cold stone floor.
DEN + NOUN
crazies, cyborg, iniquity, mother's, robbers, vice
The police raided the den of robbers that had been operating in the warehouse district for months.
PREP.
in, in, into
The children ran into the den to hide during their game of tag.