A dirty, grimy, sleazy, or disreputable person.
A poor climber, alpinist, skier or other outdoorsman who lives cheaply, without normal employment, and with few amenities in order to spend as much time on their sport as possible. Used praisingly.
A contemptible person (plural swines).
A pig (the animal).
A police officer; a "pig".
Something difficult or awkward; a pain.