Accomplish something with success, as in I'm sure he'll ace it when he takes that bar exam. The verb ace originated in tennis with the meaning “to hit an unreturnable serve against an opponent.” The idiom ace it, however, originated as student slang for getting an “A” on an exam or in a course but soon was extended to other successful accomplishments. [Slang; mid-1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.