soporific

From Wiktionary

[change] Noun

Singular soporific

Plural soporifics

1. A soporific helps you go to sleep.

[change] Adjective

Positive soporific

Comparative more soporific

Superlative most soporific

1. If something is soporific, then it will make you or almost make you go to sleep.

   The movie was soporific. I almost fell asleep.