mattock vs pick-mattock

mattock and pick-mattock both are nouns.

Word	Noun	Adjective	Verb	Adverb
mattock	Yes	No	No	No
pick-mattock	Yes	No	No	No

As nouns, pick-mattock is a hyponym of mattock; that is, pick-mattock is a word with a more specific, narrower meaning than mattock:

mattock: a kind of pick that is used for digging; has a flat blade set at right angles to the handle
pick-mattock: a versatile hand tool that combines a pick and an adze, used for grubbing in hard soils and rocky terrain.

Other hyponyms of mattock include pick mattock.

mattock (noun)	pick-mattock (noun)
a kind of pick that is used for digging; has a flat blade set at right angles to the handle	a versatile hand tool that combines a pick and an adze, used for grubbing in hard soils and rocky terrain.