Source : Webster's Revised Unabridged Dictionary (1913)

Dietary \Di"et*a*ry\, a.
   Pertaining to diet, or to the rules of diet.

Dietary \Di"et*a*ry\, n.; pl. {Dietaries}.
   A rule of diet; a fixed allowance of food, as in workhouse,
   prison, etc.

Source : WordNet®

dietary
     adj : of or relating to the diet; "dietary restrictions" [syn: {dietetic},
            {dietetical}]
     n : a regulated daily food allowance