# mistakenly

/mɪˈsteɪkənɫi/ (US) · /mɪstˈeɪkənli/ (UK)

Source: https://englishreference.com/word/mistakenly
Updated: 2026-08-08

## Senses

### 1. based on a wrong idea

adverb · CEFR B2

doing something because you believe something that is not true.

For teachers: in a manner based on a wrong judgment, belief, or misunderstanding.

- I mistakenly thought the meeting was on Tuesday, so I missed it.
- The witness mistakenly identified the suspect based on a fleeting glimpse in the poorly lit alleyway.

Usage: usually placed before the verb it modifies or at the beginning of a clause.

### 2. by accident

adverb · CEFR B2

doing something by mistake without intending to do it.

For teachers: unintentionally or by accident; performing an action in error.

- She mistakenly deleted the important file while cleaning up her desktop.
- The technician mistakenly disconnected the backup power supply during the routine maintenance check.

## Examples

- I mistakenly sent the email to the wrong person.
- The museum staff mistakenly identified the replica as an original artifact during the initial cataloging process.
- The legal team argued that the defendant had mistakenly entered the restricted area, believing it to be a public thoroughfare due to the lack of clear signage.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.