killing vs poisoning

killing and poisoning both are nouns.

Word	Noun	Adjective	Verb	Adverb
killing	Yes	Yes	No	No
poisoning	Yes	No	No	No

As nouns, poisoning is a hyponym of killing; that is, poisoning is a word with a more specific, narrower meaning than killing:

killing: the act of terminating a life
poisoning: the act of giving poison to a person or animal with the intent to kill

killing (noun)	poisoning (noun)
the act of terminating a life	the act of giving poison to a person or animal with the intent to kill
an event that causes someone to die	the physiological state produced by a poison or other toxic substance
a very large profit

killing (adjective)	poisoning (adjective)
very funny