Deletery

Del"e*ter*y, n. That which destroys. [Obs.]

They [the Scriptures] are the only deletery of heresies.
Jer. Taylor.

Del"e*ter*y (?), a. [LL. deleterius: cf. F. délétère.] Destructive; poisonous. [Obs.] "Deletery medicines." Hudibras.