E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
To run amuck. To talk or write on a subject of which you are wholly ignorant; to run foul of. The Malays, under the influence of opium, become so excited that they sometimes rush forth with daggers, yelling Amoq! amoq! (Kill ! kill !), and fall foul of any one they chance to meet.