OLIGOPSONY: A market structure dominated by a small number of large buyers controlling the buying-side of a market. Oligopsony is the somewhat obscure and seldom discussed buying counterpart to an oligopoly seller that controls the selling side of a market. Whereas oligopoly is most relevant to product markets, oligopsony is most relevant to factor markets. See also | oligopoly | monopsony | monopsonistic competition | bilateral monopoly | factor markets | market control |