Definition of Matthew's pill in English:
Matthew's pill
(also Mathew's pill)
noun
historical
A pill sold as an antidote to various poisons.
Origin
Mid 17th century; earliest use found in Newes. From the genitive of the name of Richard Mathew (died 1661), English medical practitioner, who manufactured and sold the pill + pill.
Pronunciation
Matthew's pill
/ˈmaθjuːz ˌpɪl/