soft drug vs cannabis

soft drug and cannabis both are nouns.

Word	Noun	Adjective	Verb	Adverb
soft drug	Yes	No	No	No
cannabis	Yes	No	No	No

As nouns, cannabis is a hyponym of soft drug; that is, cannabis is a word with a more specific, narrower meaning than soft drug:

soft drug: a drug of abuse that is considered relatively mild and not likely to cause addiction
cannabis: the most commonly used illicit drug; considered a soft drug, it consists of the dried leaves of the hemp plant; smoked or chewed for euphoric effect

Other hyponyms of soft drug include bhang, ganja, marihuana, marijuana, haschisch, hash, hasheesh, hashish.

soft drug (noun)	cannabis (noun)
a drug of abuse that is considered relatively mild and not likely to cause addiction	the most commonly used illicit drug; considered a soft drug, it consists of the dried leaves of the hemp plant; smoked or chewed for euphoric effect
	any plant of the genus Cannabis; a coarse bushy annual with palmate leaves and clusters of small green flowers; yields tough fibers and narcotic drugs