The word lair comes from a Germanic word for bed.
The sleeping place of a wild animal is called a lair:
The Ridgeback, singly or in a pack, will silently track the lion to its lair…
Gollum led Sam and Frodo to the lair of a giant spider called Shelob.
Because criminals–especially murderers–are frequently regarded as less than human, their homes or hiding places are often referred to as lairs:
300 Human Bones Found in Serial Killers’ Lair
Inside Adam Lanza’s lair
Generally, lair carries a negative connotation of evil, but sometimes the word is used in the sense of a cozy place to work or play:
Every writer needs a lair.
Soon he [a toddler] began rearranging the chairs, using them to form the walls of a private lair where he could hide out and look back on the world undetected.
In a police drama I watched the other night, a detective character used the word lair to refer to a criminal’s hiding place. He said the word twice; each time, he pronounced it to rhyme with layer.
Lair rhymes with pair.
In case anyone needs to practice, here are six other one-syllable words that rhyme with lair: