A sedative is a substance that induces sedation by reducing irritability or excitement.
At higher doses it may result in slurred speech, staggering gait, poor judgment, and slow, uncertain reflexes. Doses of sedatives such as benzodiazepines when used as a hypnotic to induce sleep tend to be higher than those used to relieve anxiety where as only low doses are needed to provide calming sedative effects.
Sedatives can be abused to produce an overly-calming effect (alcohol being the classic and most common sedating drug). At high doses or when they are abused, many of these drugs can cause unconsciousness (see hypnotic) and even death.