Emily Dickinson Lexicon

ONCE, adv. [wuns; from one. So D. eens, from een, and G. einst, from ein, one.]

1. One time. Trees that bear mast are fruitful but once in two years. Bacon.
2. One time, though no more. The mind once tainted with vice, is prone to grow worse and worse.
3. At one former time; formerly. My soul had once some foolish fondness for thee, / But hence 'tis gone. Addison.
4. At the same point of time; not gradually. At once the winds arise, / The thunders roll. Dryden. At once, at the same time; as, they all moved at once; hence, when it refers to two or more, the sense is, together, as one. This hath all its force at once, on the first impression. Atterbury. Once is used as a noun, when preceded by this or that; as, this once, that once.