This lexicon is intended as a tool to he lp strip aw ay one source of the endemic miscommunication and friction that now plagues both soldiers and civilians, government and non-government, who plan, coordinate, and execute the complex set of overlapping civil-military activities and tasks th at have come to characterize armed conflicts and their aftermath. Collectively known as complex operations1, they demand, but too often lack, a sense of common purpose and mutual understanding be tween a wide array of planners and practitioners, all of whom bring with them different organizational cultures, world visions, and operational approaches. These disconnects can, and too often do, create confusion, at tim es with tragic results, both on the ground and among policy-makers. Part of that confusion stem s from the widely varied vocabulary used by these m any actors. Each organization possesses their own unique terminology, perfectly clear to them, but foggy to others. Even when words look and sound familiar they often have quite different and sometimes alien meanings. Anyone who has attended an acronym and jargon -laced coordination meeting of military, civilian government, and NGO representatives knows the frustration of trying to interpret what is meant by words that have many different connotations. It is in hopes of lessening this confusion that this lexicon has been compiled.