From Longman Business Dictionarymonopsonymo‧nop‧so‧ny /məˈnɒpsəni-ˈnɑː-/ noun [uncountable] ECONOMICS a situation where there are many sellers but only one buyer for a product or serviceMany government bureaux are in the position of monopsony in buying labour, such as firemen, army officers and policemen. —monopsonist noun [countable]