The Collaborative International Dictionary of English v.0.48:

Diet \Di"et\, n. [F. di[`e]te, L. diaeta, fr. Gr. ? manner of
   living.]
   1. Course of living or nourishment; what is eaten and drunk
      habitually; food; victuals; fare. "No inconvenient diet."
      --Milton.
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   2. A course of food selected with reference to a particular
      state of health; prescribed allowance of food; regimen
      prescribed.
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            To fast like one that takes diet.     --Shak.
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   Diet kitchen, a kitchen in which diet is prepared for
      invalids; a charitable establishment that provides proper
      food for the sick poor.
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