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

See also: depressant, uninteresting

• medroxyprogesterone
• medulla
• medulla oblongata
• medulla spinalis
• medullary
• medullary ray
• medullary sheath
• medullated
• medullated nerve fiber
• medullated nerve fibre
• medusa
• medusa's head
• medusan
• medusoid
• meed
• meek
• meekly
• meekness
• meerestone
• meerkat
• meerschaum
• meet
• meet up with
• meeter
• meeting