knockabout vs rugged

knockabout is a noun but rugged is not a noun.

Word	Noun	Adjective	Verb	Adverb
knockabout	Yes	Yes	No	No
rugged	No	Yes	No	No

knockabout (noun)	rugged (noun)
a sloop with a simplified rig and no bowsprit

knockabout (adjective)	rugged (adjective)
suitable for rough use	sturdy and strong in constitution or construction; enduring
full of rough and exuberant animal spirits	having long narrow shallow depressions (as grooves or wrinkles) in the surface
	very difficult; severely testing stamina or resolution
	topographically very uneven