hashish vs soft drug

hashish and soft drug both are nouns.

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

As nouns, soft drug is a hypernym of hashish; that is, soft drug is a word with a broader meaning than hashish:

hashish: purified resinous extract of the hemp plant; used as a hallucinogen
soft drug: a drug of abuse that is considered relatively mild and not likely to cause addiction

hashish (noun)	soft drug (noun)
purified resinous extract of the hemp plant; used as a hallucinogen	a drug of abuse that is considered relatively mild and not likely to cause addiction