The Collaborative International Dictionary
Dormitive
Dormitive \Dor"mi*tive\, a. [Cf. F. dormitif, fr. dormire to
sleep.]
Causing sleep; as, the dormitive properties of opium.
--Clarke. -- n. (Med.) A medicine to promote sleep; a
soporific; an opiate.
Wiktionary
dormitive
a. Causing sleep. n. A medicine to promote sleep; a soporific or opiate.