weed vs mourning band

weed and mourning band both are nouns.

Word	Noun	Adjective	Verb	Adverb
weed	Yes	No	Yes	No
mourning band	Yes	No	No	No

As nouns, weed and mourning band are synonyms defined as:

weed and mourning band: a black band worn by a man (on the arm or hat) as a sign of mourning

weed (noun)	mourning band (noun)
street names for marijuana	a black band worn by a man (on the arm or hat) as a sign of mourning
a black band worn by a man (on the arm or hat) as a sign of mourning
any plant that crowds out cultivated plants

weed (verb)	mourning band (verb)
clear of weeds