disc plow vs moldboard plow

disc plow and moldboard plow both are nouns.

Word	Noun	Adjective	Verb	Adverb
disc plow	Yes	No	No	No
moldboard plow	Yes	No	No	No

As nouns, moldboard plow is a hypernym of disc plow; that is, moldboard plow is a word with a broader meaning than disc plow:

disc plow: a plow that consists of a gang of concave steel cutting disks, used for work in hard dry soils.
moldboard plow: plow that has a moldboard

Other hypernyms of disc plow include mouldboard plough.

disc plow (noun)	moldboard plow (noun)
a plow that consists of a gang of concave steel cutting disks, used for work in hard dry soils.	plow that has a moldboard