You won't know this word, because it is used by the Yanomami, a so-called primitive tribe of Stone-Age Indians who live in the jungles of Venezuela and Brazil. We came across this word when we visited a Yanomami village while researching our book Along the River that Flows Uphill, which describes a river-boat journey we took from the Orinoco to the Amazon.
There's no English equivalent, but nomohoni roughly means 'to employ trickery to set a trap for your enemies so they feel sufficiently secure that you can safely massacre them.'
This is a complex concept to incorporate into a single word, and most societies (fortunately) don't need it. The fact that the Yanomami do gives you a peek into their culture.