cadre

To understand cadre, we must first square our understanding of the word's Latin roots. Cadre traces to the Latin quadrum, meaning "square." Squares can make good frameworks—a fact that makes it easier to understand why first French speakers and later English speakers used cadre as a word meaning "framework." If you think of a core group of officers in a regiment as the framework that holds things together for the unit, you'll understand how the "personnel" sense of cadre developed. Military leaders and their troops are well-trained and work together as a unified team, which may explain why cadre is now sometimes used more generally to refer to any group of people who have some kind of unifying characteristic, even if they aren't leaders.