carpetweed vs weed

carpetweed and weed both are nouns.

Word	Noun	Adjective	Verb	Adverb
carpetweed	Yes	No	No	No
weed	Yes	No	Yes	No

As nouns, weed is a hypernym of carpetweed; that is, weed is a word with a broader meaning than carpetweed:

carpetweed: annual prostrate mat-forming weed having whorled leaves and small greenish-white flowers; widespread throughout North America
weed: any plant that crowds out cultivated plants

carpetweed (noun)	weed (noun)
annual prostrate mat-forming weed having whorled leaves and small greenish-white flowers; widespread throughout North America	street names for marijuana
	a black band worn by a man (on the arm or hat) as a sign of mourning
	any plant that crowds out cultivated plants

carpetweed (verb)	weed (verb)
	clear of weeds