Dictionary.net

Drugs used to induce drowsiness or sleep or to reduce psychological excitement or anxiety.

Medicines which directly depress the vital forces, and which are consequently employed whenever it is necessary to diminish preternaturally increased action. The chief reputed sedatives are: Acidum Hydrocyanicum, Acidum Hydro-sulphuricum, Tabacum, Missio Sanguinis, and certain gases by inhalation, as azote, carbonic acid[?], carburetted and sulphuretted hydrogen.