ironclad vs combat ship

ironclad and combat ship both are nouns.

Word	Noun	Adjective	Verb	Adverb
ironclad	Yes	Yes	No	No
combat ship	Yes	No	No	No

As nouns, combat ship is a hypernym of ironclad; that is, combat ship is a word with a broader meaning than ironclad:

ironclad: a wooden warship of the 19th century that is plated with iron or steel armor
combat ship: a government ship that is available for waging war

Other hypernyms of ironclad include war vessel, warship.

ironclad (noun)	combat ship (noun)
a wooden warship of the 19th century that is plated with iron or steel armor	a government ship that is available for waging war

ironclad (adjective)	combat ship (adjective)
inflexibly entrenched and unchangeable
sheathed in iron plates for protection
without flaws or loopholes