somniferous vs soporiferous

somniferous and soporiferous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
somniferous	No	Yes	No	No
soporiferous	No	Yes	No	No

As adjectives, somniferous and soporiferous are synonyms defined as:

Other synonyms of somniferous include hypnagogic, hypnogogic, somnific, soporific.

somniferous (adjective)	soporiferous (adjective)
sleep inducing	sleep inducing
	inducing mental lethargy