mix up

1 of 2

verb

mixed up; mixing up; mixes up

1

: to mistakenly think that (someone or something) is someone or something else : confuse

mixed the twins up

mixed up the times for the meetings

2

: to mistakenly put (something) in a place where something else should be

mixed up the two files

3

: to cause (someone) to be involved in a usually dangerous or improper activity

—usually used as (be/get) mixed up in

got mixed up in an illegal scheme

4

: to cause (someone) to become involved with usually bad or dangerous people

mix-up

2 of 2

noun

ˈmiks-ˌəp 

1

: a state or instance of confusion

a mix-up in our hotel reservations

2

: mixture

3

: conflict, fight

Synonyms of mix up

Noun

• mistake
• confusion
• foul-up

Examples of mix up in a Sentence

Noun

there was a mix-up at the airport and our luggage was accidentally sent to Ohio

Recent Examples on the Web

Noun

Ultimately, that mix-up is apt foreshadowing. —Tom Smyth, Vulture, 9 Dec. 2025

This novel is much more than a story of a possible hospital mix-up of babies. —Mary Ann Grossmann, Twin Cities, 30 Nov. 2025

What should have been a forgettable mix-up instead bloomed into an annual Thanksgiving reunion — and a friendship that has carried both Wanda Dench and Jamal Hinton through loss, new beginnings and some of life’s most unexpected blessings. —Moná Thomas, PEOPLE, 26 Nov. 2025

According to Jensen, the mix-up began after Bailey had spent time happily fetching his own ball in the sea. —Alice Gibbs, MSNBC Newsweek, 13 Nov. 2025

Word History

First Known Use

Noun

1841, in the meaning defined at sense 1

Kids Definition

mix-up

noun

ˈmik-ˌsəp

: an instance of confusion