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.
Satire's my weapon, but I'm too discreet To run amuck and tilt at all I meet.
Pope: Sattires, i. 69–70.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894