1. Sleep inducing
   - soporific, soporiferous, somniferous, hypnogogic, hypnagogic

See also: depressant

• hard rubber
• hard rush
• hard sauce
• hard sell
• hard shoulder
• hard solder
• hard steel
• hard surface
• hard tick
• hard time
• hard times
• hard up
• hard water
• hard wheat
• hard worker
• hard-and-fast
• hard-baked
• hard-bitten
• hard-boiled
• hard-boiled egg
• hard-cooked egg
• hard-fought
• hard-hitting
• hard-nosed
• hard-of-hearing