"soporific" in the noun sense
1. soporific, hypnotic
a drug that induces sleep
"soporific" in the adjective sense
1. soporific, soporiferous, somniferous, somnific, hypnogogic, hypnagogic
sleep inducing
2. narcotic, soporiferous, soporific
inducing mental lethargy
"a narcotic speech"
Source: WordNet® (An amazing lexical database of English)
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