slang To improve the performance or appearance of something by customizing it with new components or decorations. A noun or pronoun can be used between "mack" and "out." I bought a car for less than $2,000, then macked it out with speakers, new tires, and a sick paint job. The company urges people to bring in their old, beat-up computers and let their team of engineers mack out the old machines, rather than throw them away and buy brand new ones.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.