For a group of men (agent muɴ- & theme) to go on a headhunting raid.
A raiding party traditionally consisted of about five to ten men usually from a single clan. Heads, hewat, and often arms and/or legs, pūtel, were cut off, brought home and a ceremony, ha'dol 3b, was performed).
For someone (actor -um- & theme) to waylay an enemy (loc ref -on) with an offensive weapon, as a spear, bangkaw (inst i-), for the purpose of taking a head in revenge.