Emily Dickinson Lexicon

ACE, n. [L. as, a unit or pound; Fr. as; It. asso; D. aas; G. ass; Sp. as.]

1. A unit; a single point on a card or die; or the card or die so marked.
2. A very small quantity; a particle; an atom; a trifle; as, a creditor will not abate an ace of his demand.