longshoreman vs dock worker

longshoreman and dock worker both are nouns.

Word	Noun	Adjective	Verb	Adverb
longshoreman	Yes	No	No	No
dock worker	Yes	No	No	No

As nouns, longshoreman and dock worker are synonyms defined as:

longshoreman and dock worker: a laborer who loads and unloads vessels in a port

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

longshoreman (noun)	dock worker (noun)
a laborer who loads and unloads vessels in a port	a laborer who loads and unloads vessels in a port