エース

ace(noun)

the one in playing-cards

the ace of spades.

第一人者

ace(noun)

a person who is expert at anything

He's an ace with a rifle.

サービスエース

ace(noun)

a serve in tennis in which the ball is not touched by the opposing player.

（ドミノ・さいころなどの）１

ace(noun)

the ``one'' on dominoes or dice.