lockkeeper vs skilled worker

lockkeeper and skilled worker both are nouns.

Word	Noun	Adjective	Verb	Adverb
lockkeeper	Yes	No	No	No
skilled worker	Yes	No	No	No

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

Other hypernyms of lockkeeper include skilled workman, trained worker.

lockkeeper (noun)	skilled worker (noun)
a worker in charge of a lock (on a canal)	a worker who has acquired special skills