Entry 2 senses · 2 variants Webster, 1913 Dietary /dī'-ət-ĕrˌ-ē/ · Di·et·a·ry · IPA /ˈdaɪət(ə)ɹi/ a. n. 01 a. Pertaining to diet, or to the rules of diet. 1. Pertaining to diet, or to the rules of diet. 02 n. A rule of diet; a fixed allowance of food, as in workhouse, prison, etc. pl. Dietaries 1. A rule of diet; a fixed allowance of food, as in workhouse, prison, etc.