1. Sleep inducing
   - soporific, somniferous, somnific, hypnogogic, hypnagogic 
2. Inducing mental lethargy
   - narcotic, soporific

See also: depressant, uninteresting

• inactively
• inactiveness
• inactivity
• inadequacy
• inadequate
• inadequately
• inadequateness
• inadmissibility
• inadmissible
• inadvertence
• inadvertency
• inadvertent
• inadvertently
• inadvisability
• inadvisable
• inadvisably
• inaesthetic
• inalienability
• inalienable
• inalienably
• inalterable
• inamorata
• inamorato
• inane
• inanely