The Killers of the Flower Moon Glossary defines allotment as “the share of surface land given to each Osage on the tribal roll after the U.S. government had forced the breakup of their communal reservation” (300). Every three months, the Osage population would lease their allotments to oil companies in a dramatic auction. At the height of the oil craze, a single allotment could be leased for over a million dollars.

The Killers of the Flower Moon Glossary defines black gold as “another name for oil” (300). This substitute for oil is only used twice in the book, first to describe the suspicion that Mollie’s family was being killed for their money and access to oil. David Grann mentions “black gold” a second time when he watches a video production of Wahzhazhe, an Osage ballet depicting the people's history.

The Killers of the Flower Moon Glossary defines boomtown as “a town enjoying very fast growth in business success and population” (300). The boomtowns in this story are the backdrop to the crimes committed against the Osage people.