a laborer who helps to load and unload ships; longshoreman
Word origin
, lump1 verb transitive + -er
lumper in American English
(ˈlʌmpər)
noun
1.
a day laborer employed to handle cargo, as fish or timber
2. Biology informal
a taxonomist who believes that classifications should emphasize similarities among organisms and therefore favors large, inclusive taxa (opposed to splitter)