Lumper is a slang expression, referring to people doing physical labor for a living, by hauling massive lumps all day – lump, in the sense of an object with a large mass and an undefined shape.
“Lumper” derives from the word lump referring to a solid object, with lump most likely coming to English from continental or Scandinavian languages by the 14th century.
“Lumper” written sources start mentioning it in its current sense at the end of the 18th century, however, the word appears as a verb in the 1581 manuscript of John Daye: “Against Ieorme Osorivs”.
“Lumper” spread in the subsequent centuries, especially following the industrial revolution in the 1800’s, which spawned a historical high in manual laborers, with having to resort to hauling product and material in order to survive.
Over the 1900’s, the popularity of the word “Lumper” remained consistent, with a slight surge in the 1980’s.
It was first defined on Urban Dictionary on November 6th, 2004, with several other entries following.