1 B1 idiomatic informal
To confuse one thing with another by mistake.
"I always muddle up 'affect' and 'effect' — they seem identical to me."
separable
muddle up
B1 informal separable transitive
To confuse two or more things, or to put things into a disordered mess.
In plain English
To mix things up by accident so that they're in the wrong order or confused with each other.
What does "muddle up" mean?
2 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B1 idiomatic informal
To put things into disorder; to create a mess or confusion.
"Someone has muddled up all the filing — these documents are in completely the wrong order."
separable
Usage tip
Common in British English. Used both for physical things (papers, objects) and abstract things (names, facts, dates). 'Muddled up' is a common adjective meaning confused or disordered.
Words that pair with "muddle up"
Natural word combinations native speakers use most often.
names dates files orders facts papers
How to conjugate "muddle up"
The five tense forms you'll use most often.
Base
muddle up
I/you/we/they
3rd person
muddles up
he/she/it
Past simple
muddled up
yesterday
Past participle
muddled up
have + pp
-ing form
muddling up
continuous
Hear "muddle up" in the wild
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