steerer vs mariner

steerer and mariner both are nouns.

Word	Noun	Adjective	Verb	Adverb
steerer	Yes	No	No	No
mariner	Yes	No	No	No

As nouns, mariner is a hypernym of steerer; that is, mariner is a word with a broader meaning than steerer:

Other hypernyms of steerer include gob, Jack-tar, Jack, old salt, sea dog, seafarer, seaman, tar.

steerer (noun)	mariner (noun)
a beguiler who leads someone into danger (usually as part of a plot)	a man who serves as a sailor
the person who steers a ship