amok (adv.)

in run amok a verbal phrase first recorded 1670s, from Malay (Austronesian) amuk "attacking furiously." Earlier the word was used as a noun or adjective meaning "a frenzied Malay," originally in the Portuguese form amouco or amuco.

There are some of them [Javanese] who ... go out into the streets, and kill as many persons as they meet. ... These are called Amuco. ["The Book of Duarte Barbosa: An Account of the Countries Bordering on the Indian Ocean and Their Inhabitants," c. 1516, English translation]

Compare amuck.

Others are reading

Definitions of amok from WordNet
amok (adv.)
wildly; without self-control;
Synonyms: amuck
amok (adv.)
in a murderous frenzy;
Synonyms: amuck / murderously
amok (adj.)
wildly frenzied and out of control;
Synonyms: amuck / berserk