# spy

/ˈspaɪ/ (US) · /spˈaɪ/ (UK)

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

## Senses

### 1. secret agent

noun · CEFR B1

a person who secretly collects information about an enemy, a government, or a business.

For teachers: an individual employed by a government or organisation to collect secret information regarding a competitor or enemy.

- The spy was caught trying to steal secret documents from the embassy.
- Intelligence agencies often spend years cultivating a single spy within a foreign government to ensure a steady flow of high-level information.

### 2. to watch secretly

verb · CEFR B1

to watch someone or something secretly to find out information.

For teachers: to observe a person, group, or country secretly and continuously. Often takes the preposition 'on'.

- The children liked to spy on their older brother from the treehouse.
- The corporation was accused of hiring private investigators to spy on its competitors' research and development facilities.

Usage: Commonly used with the preposition 'on' followed by the target.

### 3. to catch sight of

verb · CEFR C1 · Literary

to suddenly see or notice something, especially something far away or hidden.

For teachers: to catch sight of or detect something through careful observation. Transitive in this sense.

- From the top of the hill, she managed to spy a small cottage in the valley.
- After hours of scanning the horizon with his binoculars, the lookout finally spied a thin plume of smoke rising from the distant island.

### 4. football defender

noun · CEFR C2 · American English · Technical

a player in American football whose job is to watch and follow a specific opponent.

For teachers: a defensive player assigned to mirror the movements of a specific offensive player, typically the quarterback, to prevent a run.

- The coach decided to use a linebacker as a spy to stop the quarterback from running.
- By employing a fast linebacker as a spy, the defense successfully neutralised the quarterback's ability to scramble for first downs.

Usage: Used as a countable noun in a sports strategy context.

## Examples

- The spy hid the secret documents in a hollow book.
- During the war, the spy lived in the enemy capital for years without being caught.
- Modern intelligence gathering relies heavily on digital surveillance, yet the role of the human spy remains vital for understanding the personal motivations of foreign leaders.

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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.