Introduce the dictionary by name. For example: "The Oxford English Dictionary."
Give the definition. For example: "The Oxford English Dictionary defines 'moulin' as 'A vertical shaft in a glacier, formed by surface water percolating through a crack in the ice.'"
Write the edition and date of publication of the dictionary cited within parentheses. For example "The Oxford English Dictionary defines 'moulin' as 'A vertical shaft in a glacier, formed by surface water percolating through a crack in the ice.' (7th ed., 2000)."
Include a full citation of the specific dictionary within your work's references section. For example: "Moulin. (2000). In C. Soanes (Ed.), Oxford English Dictionary (929, 7th ed., vol. 1). New York: Oxford University Press."