The word “lair” /lɛːɺ/ refers to where an animal lies or rests, or less often to clay or wet earth or still less often to an ostentatiously dressed man.
The word “liar” /ˈlʌɪəɺ/ refers to one who knowingly delivers falsehoods, with intent to deceive.
(People who extend their pinkies when they speak will not pronounce the ‘r’ of either word.)