Emily Dickinson Lexicon

FAST, v.i. [Sax. fæstan, Goth. fastan, to fast, to keep, to observe, to hold; G. fasten; D. vast, firm; vasten, to fast; Sw. fasta; from the same root as fast, firm. The sense is to hold or stop.]

1. To abstain from food, beyond the usual time; to omit to take the usual meals, for a time; as, to fast a day or a week.
2. To abstain from food voluntarily, for the mortification of the body or appetites, or as a token of grief, sorrow and affliction. Thou didst fast and weep for the child. 2 Sam. xii. When ye fast, be not, as the hypocrites, of a sad countenance. Matth. vi.
3. To abstain from food partially, or from particular kinds of food; as, the Romanists fast in Lent.