Noun
An alkaloid found in the Calabar bean (the seed of Physostigma venenosum), and extracted as a white, tasteless, substance, amorphous or crystalline; -- formerly called eserine, with which it was regarded as identical.
Source: Webster's dictionaryMary Walker treated a person with MG with physostigmine in 1934. Source: Internet
The drug physostigmine is used to reverse the effect of the poisons. Source: Internet