# mysteriously

/ˌmɪsˈtɪɹiəsɫi/ (US) · /mɪstˈiəɹɪəsli/ (UK) · CEFR B2 · Adverb

Source: https://englishreference.com/word/mysteriously
Updated: 2026-05-07

## Definition

in a way that is strange and difficult to explain. You use this when something happens and you do not know why or how it happened.

For teachers: in a manner that is difficult or impossible to understand, explain, or identify. Often used to describe events that seem to lack a logical cause.

## Examples

- The lights in the old house mysteriously turned on.
- The ancient documents mysteriously disappeared from the locked safe overnight without any sign of a break-in.
- The species, which had thrived for centuries in the isolated valley, mysteriously vanished from the fossil record long before the arrival of human settlers.

## Usage notes

- Typically placed after the verb or at the end of the clause to describe the nature of an action.

---

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.