Something that quietens; a sedative.
Tending to quieten or make passive.
The act of calming a person or animal, or putting them to sleep, using a drug.
The act of making someone or something tranquil.
Of a drug: having the effect of calming a person or animal, or putting them to sleep; sedating, sedative.
Having the effect of making someone or something tranquil; calming, soothing.