Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
Informal very good; excellent
Used by arrangement with John Wiley & Sons, Inc.
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Very good; excellent: did a bang-up job on the test.
Origin: From bang1.
bang-up - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Damage, injure, as in Banging up the car a second time will make Dad very unhappy, or Mother fell down the stairs and was all banged up. The verb to bang alone had this meaning from the 1500s on, up being added in the late 1800s. In the early 1800s it gave rise to the colloquial adjective bang-up, for excellent or very successful, as in David did a bang-up job baking the birthday cake.