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

See also: depressant, uninteresting

• cytogenesis
• cytogenetic
• cytogenetical
• cytogeneticist
• cytogenetics
• cytogeny
• cytokine
• cytokinesis
• cytokinetic
• cytokinin
• cytol
• cytologic
• cytologic smear
• cytologic specimen
• cytological
• cytologist
• cytology
• cytolysin
• cytolysis
• cytolytic
• cytomegalic
• cytomegalovirus
• cytomembrane
• cytopathogenic
• cytopenia