muddy the waters, to

muddy the waters

To introduce something, typically information, to an issue or situation that makes it less clear or more confusing. Don't muddy the waters with unrelated issues—we need to focus on this one problem. The last witness's testimony has muddied the waters, and most likely doubt has entered the minds of the jury members.
See also: muddy, water
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

muddy the waters

Confuse the issue, as in Bringing up one irrelevant fact after another, he succeeded in muddying the waters. This metaphoric expression, alluding to making a pond or stream turbid by stirring up mud from the bottom, was first recorded in 1837.
See also: muddy, water
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.

muddy the waters

If someone or something muddies the waters, they make a situation or an issue more confusing and complicated. The society has been accused of trying to muddy the waters through its poll which has been described as `misleading'. This ruling seems only to have muddied the waters and we are seeking clarification.
See also: muddy, water
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012

muddy the waters

make an issue or a situation more confusing and harder to understand by introducing complications.
The figurative use of muddy to mean ‘make something hard to perceive or understand’ occurs in Shakespeare ; muddy the waters dates from the mid 19th century.
See also: muddy, water
Farlex Partner Idioms Dictionary © Farlex 2017

muddy the ˈwaters

(disapproving) make something which seemed clear and easy to understand before seem much less clear now: Recent research findings have muddied the waters considerably — nuclear scientists are having to re-examine all their existing theories.They’re just muddying the waters with all this new information.
See also: muddy, water
Farlex Partner Idioms Dictionary © Farlex 2017

muddy the waters, to

To confuse the issue. This analogy to stirring up the mud from the bottom of a clear pond, lake, or stream dates from the early nineteenth century. The OED quotes Blackwell’s Magazine (1837): “He . . . began to muddy the water.”
See also: muddy
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
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