wireman vs skilled workman

wireman and skilled workman both are nouns.

Word	Noun	Adjective	Verb	Adverb
wireman	Yes	No	No	No
skilled workman	Yes	No	No	No

As nouns, skilled workman is a hypernym of wireman; that is, skilled workman is a word with a broader meaning than wireman:

Other hypernyms of wireman include skilled worker, trained worker.

wireman (noun)	skilled workman (noun)
a worker who installs and repairs electric wiring	a worker who has acquired special skills