lumper vs longshoreman

lumper and longshoreman both are nouns.

Word	Noun	Adjective	Verb	Adverb
lumper	Yes	No	No	No
longshoreman	Yes	No	No	No

As nouns, lumper and longshoreman are synonyms defined as:

lumper and longshoreman: a laborer who loads and unloads vessels in a port

Other synonyms of lumper include dock-walloper, dock worker, docker, dockhand, dockworker, loader, stevedore.

lumper (noun)	longshoreman (noun)
a taxonomist who classifies organisms into large groups on the basis of major characteristics	a laborer who loads and unloads vessels in a port
a laborer who loads and unloads vessels in a port