Stupefacient

Stu′pe‐fa″cient (?), a. [L. stupefaciens, p. pr. of stupefacere to stupefy; stupere to be stupefied + facere to make. Cf. Stupefy.] [Written also stupifacient.] Producing stupefaction; stupefactive. — n.(Med.) Anything promoting stupefaction; a narcotic.