Is it ensure, insure, or assure?
c.1400, intoxigacion "poisoning," from Medieval Latin intoxicationem (nominative intoxicatio) "poisoning," noun of action from past participle stem of intoxicare (see intoxicate). Meaning "drunkenness" is from 1640s.
intoxication in·tox·i·ca·tion (ĭn-tŏk'sĭ-kā'shən)
The pathological state produced by a drug, serum, alcohol, or any toxic substance; poisoning.
A state of mental excitement or emotional frenzy.