mithridatize

 
Pronunciation: /mɪˈθrɪdətʌɪz/
(also mithridatise)

verb

[with object] rare
  • make (someone) immune to a poison by administering gradually increasing doses of the poison.

Origin:

mid 19th century: from the name of Mithridates (see Mithridates VI), who reputedly made himself immune to poisons by constantly taking antidotes, + -ize