Definition of "lumper"

lumper¹

noun
plural lumpers
1. An extra laborer hired to assist in the loading or unloading of a truck or a ship.
  Quotations
  There were owners of lines of schooners, large contributors to the societies, and small men, their few craft pawned to the mastheads, with bankers and marine-insurance agents, captains of tugs and water-boats, riggers, fitters, lumpers, salters, boat-builders, and coopers, and all the mixed population of the water-front.
  1896 November – 1897 May, Rudyard Kipling, “Captains Courageous”, Garden City, N.Y.: Doubleday & Company, published 1897
2. (biology, linguistics) A scientist in one of various fields who prefers to keep categories such as species or dialects together in larger groups.
3. (dialect) A militiaman.

lumper²

noun
plural lumpers
1. (dialect) A lamprey.

lumper³

verb
third-person singular simple present lumpers, present participle lumpering, simple past and past participle lumpered
1. to lumber; to plod
  Quotations
  Over piggeries, and mixens, and apples, and hay, / They lumpered straight into the night; / And finding bylong where a halter-path lay, / At dawn reached Tim's house […]
  1866 (date written), Thomas Hardy, “The Fire at Tranter Sweatley’s”, in Wessex Poems and Other Verses, New York, N.Y., London: Harper & Brothers, published 1898, page 190
  But, my dear woman, why ever have ye come lumpering up to Rainbarrows at this time o' night?
  1904, Thomas Hardy, The Dynasts: A Drama of the Napoleonic Wars, […], part first, London: Macmillan and Co.: New York, N.Y.: The Macmillan Company, Act II, scene v, page 81
  Lord, what's the good o' my lumpering all the way to church and back again, when I'm as deaf as a plock?
  1929, Thomas Hardy, Old Mrs. Chundle, New York: Crosby Gaige, page 11