an expression used to show that something is very dark or very black. An
ace is a playing
card marked in the center with one large
mark or
spot (usually black or
red in
color) and an "A"
marked in two of its corners. Depending on the
game played, it can have the highest or lowest
value in a
pack of cards. A spade is a black figure shaped like an upside-down heart with a
short stem opposite the
point, and is one of the
symbols used on playing cards. Thus, the
phrase black as the
ace of spades means that something is very black, like the
blackness of the spade in a
pack of cards.