The unit of cards or dice, from as>, the Latin unit of weight. (Italian, asso; French and Spanish, as.)
Within an ace.
Within a shave. An ace is the lowest numeral, and he who wins within an ace, wins within a single mark. (See Ambes-As.)
To bate an ace
is to make an abatement, or to give a competitor some start or other advantage, in order to render the combatants more equal. It said that the expression originated in the reign of Henry VIII, when one of the courtiers named Bolton, in order to flatter the king, used to say at cards, “Your Majesty must bate me an ace, or I shall have no chance at all.” Taylor, the water poet (1580–1654), speaking of certain women, says—
Though bad they be, they will not bate an ace To be cald Prudence, Temprance, Faith, and Grace.