The words 'Mau Mau' themselves come from the oath that was taken at the clandestine meetings.
Knowing full well that the white settlers would send their Kikuyu servants to spy on the meetings and report back to their masters, the attendees were bound never to repeat what they heard or saw to anyone else.
If asked about the meeting they were only to say, " Maundu mau, maundu mau" or in English, "those things, those things."
The resistance movement was headed by many veterans of the British campaign in Burma during World War 2 and the relative success of their campaign of guerilla warfare was as a direct result of their training in jungle warfare.