soporific
/sɒpəˈrɪfɪk/Definitions
1. adjective
causing drowsiness or sleep
“The soporific effect of the warm sun on the beach made me fall asleep.”
2. noun
a substance or agent that induces sleep or drowsiness
“The soporific gas was used to sedate the patients.”
3. noun
something that causes weariness or boredom
“The long, soporific lecture put the audience to sleep.”