dock worker vs longshoreman

dock worker and longshoreman both are nouns.

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

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

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

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

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