Definition of lavatory humor in US English:

lavatory humor

noun

British
  • Humor that is characterized by coarse references to bodily functions.

    ‘this is a land renowned for its lavatory humor’
    • ‘Their effort at comedy is simply obnoxious and unfunny as it takes cheap shots at race, midgets, and mental illness, along with the usual lavatory humour.’
    • ‘There would be few adults who could say that their childhood was completely devoid of lavatory humour.’
    • ‘Lavatory humour, provided it isn't over the top, usually amuses a wide cross section of people.’
    • ‘The article is sadly representative of the offensive, schoolboy, lavatory humour which masquerades as entertainment in a number of programmes.’
    • ‘He is the incarnation of the ocker, with his lavatory humour.’