atrazine vs weed killer

atrazine and weed killer both are nouns.

Word	Noun	Adjective	Verb	Adverb
atrazine	Yes	No	No	No
weed killer	Yes	No	No	No

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

atrazine: a synthetic compound derived from triazine that is widely used as an agricultural herbicide
weed killer: a chemical agent that destroys plants or inhibits their growth

Other hypernyms of atrazine include herbicide, weedkiller.

atrazine (noun)	weed killer (noun)
a synthetic compound derived from triazine that is widely used as an agricultural herbicide	a chemical agent that destroys plants or inhibits their growth