The Collaborative International Dictionary of English v.0.48:

Fast \Fast\, v. i. [imp. & p. p. Fasted; p. pr. & vb. n.
   Fasting.] [AS. f[ae]stan; akin to D. vasten, OHG.
   fast[=e]n, G. fasten, Icel. & Sw. fasta, Dan. faste, Goth.
   fastan to keep, observe, fast, and prob. to E. fast firm.]
   1. To abstain from food; to omit to take nourishment in whole
      or in part; to go hungry.
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            Fasting he went to sleep, and fasting waked.
                                                  --Milton.
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   2. To practice abstinence as a religious exercise or duty; to
      abstain from food voluntarily for a time, for the
      mortification of the body or appetites, or as a token of
      grief, or humiliation and penitence.
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            Thou didst fast and weep for the child. --2 Sam.
                                                  xii. 21.
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   Fasting day, a fast day; a day of fasting.
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