muck up

muck up idiom
Bungle, damage, make a mess of, as in Don't let him write the review; he's sure to muck it up. This idiom alludes to the verb muck in the sense of “spread manure on.” [Early 1900s] For a synonym, see foul up.

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.

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