device

device — noun

1. A tool or piece of equipment created to perform a specific job or function — for

1.nounB1
Definition

A tool or piece of equipment created to perform a specific job or function — for example, a thermometer that measures body temperature or a pulley that lifts building materials.

Example

Eve used a small device to check her blood pressure every morning.

device + to-infinitive for purpose

A simple pulley device lifts heavy boxes onto the delivery truck.

Common collocations
  • medical device
  • tracking device
  • safety device
  • handheld device
  • clever device
Synonyms
  • tool

    more general; a device is often more mechanical or electronic than a simple tool

  • appliance

    typically used for larger household or kitchen devices

  • instrument

    suggests precision or scientific use

  • gadget

    informal; suggests a small, cleverly designed device

Grammar Patterns

device + for + [gerund]

device + to + [infinitive]

2. A portable electronic item like a phone, tablet, or laptop that is able to go on

2.nounA2
Definition

A portable electronic item like a phone, tablet, or laptop that is able to go online and hold information.

Example

Adaeze keeps all her photos on a single device so she can find them quickly.

on a device

Many students now use a mobile device to take notes in class instead of paper.

mobile device

Common collocations
  • mobile device
  • smart device
  • handheld device
  • electronic device
  • on a device
  • connect to a device
Synonyms
  • gadget

    informal; suggests a small, modern electronic item

  • hardware

    refers to the physical components of computers and electronics

Grammar Patterns

device + for + [gerund]

mobile / handheld / smart + device

Usage Note

In this sense, device is almost always preceded by a modifier such as mobile, smart, handheld, or electronic. Using device alone can feel vague in a technology context — specify the kind of device when possible.

Common Mistakes

I left my device at home and could not call anyone.
I left my phone at home and could not call anyone.
When you know what kind of device you mean, name it. 'Device' alone sounds vague in everyday conversation.

3. A method, technique, or way of using language that is designed to create a parti

3.nounB2
Definition

A method, technique, or way of using language that is designed to create a particular effect, especially in writing, speeches, or art — for example, using a flashback in a film to create suspense.

Example

The novelist uses the device of an unreliable narrator to keep readers guessing.

literary device: unreliable narrator

Karim made his speech more persuasive by repeating a key phrase as a device.

Common collocations
  • literary device
  • rhetorical device
  • narrative device
  • stylistic device
  • dramatic device
Synonyms
  • technique

    more general; 'device' implies a deliberate artistic or rhetorical effect

  • ploy

    more negative; suggests a trick rather than a legitimate technique

Grammar Patterns

literary / rhetorical / narrative + device

Usage Note

Often paired with an adjective that names the type of technique: literary device, rhetorical device, narrative device, or stylistic device. Distinguish from sense 1 (TOOL OR MACHINE) — this sense is always abstract, never a physical object.

4. An explosive object such as a bomb, made to detonate and harm people or property

4.nounB2
Definition

An explosive object such as a bomb, made to detonate and harm people or property.

Example

The police safely removed the device before anyone got hurt.

Eitan heard on the news that an explosive device was found near the train station.

explosive device

Common collocations
  • explosive device
  • improvised explosive device
  • incendiary device
  • nuclear device
Synonyms
  • bomb

    more direct and common in everyday language

  • explosive

    refers to the substance rather than the container or mechanism

Grammar Patterns

explosive / incendiary + device

Usage Note

In news and official reports, this sense often appears with the modifier explosive or improvised (as in IED — Improvised Explosive Device). Using device alone in this context is understood as a euphemism for bomb.

5. A clever plan or trick designed to achieve something, often by deceiving or mani

5.nounC1
Definition

A clever plan or trick designed to achieve something, often by deceiving or manipulating others — for example, pretending to be someone else in order to gain access to a building.

Example

Christopher saw through his opponent's device and refused to be fooled.

see through a device

The con artist's device: pretend to need help while a partner takes the wallet.

Common collocations
  • clever device
  • see through a device
  • a device for [gerund]
Synonyms
  • trick

    more general and less formal; can be harmless or dishonest

  • ploy

    similar negative tone but often suggests a brief, tactical move

  • stratagem

    more formal; often used in military or political contexts

Grammar Patterns

device for + [gerund]

Usage Note

This sense has a negative connotation — it implies dishonesty or manipulation. Distinguish from sense 3 (METHOD OR TECHNIQUE), which is neutral or artistic. If the trick is harmless or playful, use trick instead.

Idioms

leave (somebody) to their own devices

idiom

To allow someone to do whatever they want without giving them instructions, help, or supervision.

The teacher left the advanced students to their own devices while she helped the beginners.

When Stephanie's parents went out, they left her to her own devices for the evening.

leave somebody to their own devices

idiom

To allow someone to do whatever they want without giving them instructions or help.

The teacher left the students to their own devices for the project.

When Sara's parents went out, they left her to her own devices.

Word family

Synonym discussion

Sense: noun/1

All five words refer to something used to perform a task, but they differ in scope and register. Device is the broadest term — it covers anything from a simple bottle opener to a complex smartphone. Tool usually refers to a hand-held implement for manual work (hammer, screwdriver), while gadget is informal and suggests a small, cleverly designed item (a fitness tracker, a smart key finder). Instrument implies precision or scientific use (a surgical instrument, a measuring instrument). Appliance is reserved for larger household machines (a refrigerator, a washing machine). Choosing among them depends on size, purpose, and formality: 'Which gadget is that on your wrist?' but 'The hospital bought an expensive imaging device.'

tool ↗gadget ↗instrument ↗appliance ↗device ↗

Common collocations

Nouns

  • device type
  • device model
  • device manufacturer

Adverbs

Phrases

  • state-of-the-art device
  • purpose-built device
  • handheld device

Prepositions

  • in a device
  • on a device
  • with a device
  • by device of

Etymology

LatinOld FrenchMiddle EnglishEnglish

The word 'device' entered English in the 13th century from Old French 'devis', meaning 'division, plan, or design'. This came from Latin 'divisus', the past participle of 'dividere' (to divide). The original sense was 'something planned or contrived', which later split into two branches: the meaning of 'mechanical invention' (1300s) and the meaning of 'artistic or rhetorical technique' (1500s). The 'explosive weapon' meaning emerged in the 20th century.