Answer:
Latin
Step-by-step explanation:
Soporific is a word of Latin origin, we can see this through the letter L, right at the beginning of the description: [L sopor sopor + -i- + -fic; cf. F soporifique], which shows that this word originates from the word "sopor" in Latin.
Soporific refers to something candid, dull and discouraging.