Definition of blue pill in English:

blue pill

noun

historical
  • 1Pharmacology
    Pharmacology. Any of various medicinal preparations containing metallic mercury or a compound of mercury, used especially in the treatment of syphilis and disorders of the liver, and as a purgative; (as a count noun) a tablet of such a preparation.

  • 2US
    slang USslang. A bullet. Now historical.

Origin

Late 17th century; earliest use found in Gideon Harvey (c1636–?1702), physician. From blue + pill.

Pronunciation

blue pill

/ˌbluː ˈpɪl/