# detected

/dɪˈtɛktəd/ (US) · /dɪtˈɛktɪd/ (UK)

Source: https://englishreference.com/word/detected
Updated: 2026-06-19

## Senses

### 1. to notice or discover

verb · CEFR B2

to have found or noticed something that was hard to see or hidden.

For teachers: to have discovered or identified the presence of something, especially something subtle, hidden, or faint.

- The security system detected a small movement in the hallway late at night.
- The laboratory equipment detected trace amounts of the chemical in the water supply, prompting an immediate investigation by the local authorities.

Usage: Often used in the passive voice when describing scientific or criminal findings.

### 2. having been noticed

adjective · CEFR B2

describing something that has been seen or found by a person or a machine.

For teachers: referring to an object, signal, or quality that has been successfully identified or perceived.

- The error remained detected but uncorrected for several weeks.
- Once the signal was detected, the researchers began the process of triangulating its point of origin across the desert.

Usage: Usually functions as a predicative adjective or within a passive construction.

Teaching tip: Learners should be aware that 'undetected' is actually more common as a standalone adjective than 'detected'.

## Examples

- The sensor detected a small gas leak.
- The airport security scanner detected a metal object in the passenger's carry-on bag.
- Astronomers detected faint gravitational waves that confirm theories about how massive objects move through the universe, marking a significant breakthrough in modern physics.

---

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.