# ECO

/ˈɛkoʊ/ (US)

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

## Senses

### 1. environmentally friendly

adjective · CEFR B1

a short way to say 'ecological' — used for products or habits that do not hurt the planet.

For teachers: a clipping of 'ecological', denoting products, services, or practices designed to minimize environmental impact.

- We decided to buy an eco car to reduce our carbon footprint.
- The new housing development features several eco initiatives, including rainwater harvesting and solar-powered street lighting.

Usage: Often used as a prefix with a hyphen (eco-friendly) or as a standalone modifier.

### 2. saving money or energy

adjective · CEFR B1

a short way to say 'economy' — used for settings on machines that use less electricity or water.

For teachers: a clipping of 'economy', specifically referring to a functional mode on appliances designed for resource efficiency.

- I always run the dishwasher on the eco setting to save on my electric bill.
- Modern washing machines typically include an eco cycle that operates at lower temperatures for a longer duration to conserve energy.

Usage: Commonly found on control panels and in user manuals for household appliances.

### 3. eternally collapsing object

noun · CEFR C2 · Technical · Academic

Stands for Eternally Collapsing Object — a theoretical type of star that is like a black hole but never quite finishes collapsing.

For teachers: Abbreviation for Eternally Collapsing Object. A theoretical alternative to black holes in astrophysics that avoids the formation of a singularity.

- The professor explained how an ECO differs from a traditional black hole model.
- Recent theoretical papers suggest that what we observe as black holes might actually be ECOs, which lack a true event horizon.

Usage: Used as a countable noun in theoretical physics contexts.

### 4. engine cutoff

noun · CEFR C1 · Technical

Stands for Engine Cutoff — the moment when a rocket engine stops working, usually after it runs out of fuel.

For teachers: Abbreviation for Engine Cutoff. The scheduled or unscheduled termination of a rocket engine's combustion cycle.

- The mission control team confirmed ECO three minutes after the launch.
- The primary objective was achieved shortly before the main engine cutoff (ECO) occurred during the second stage of ascent.

Usage: Common in aerospace engineering and NASA communications.

### 5. West African currency

noun · CEFR B2 · Academic

the name for a new shared currency planned for several countries in West Africa.

For teachers: The proposed name for a common currency intended for use by the Economic Community of West African States (ECOWAS).

- Many people are waiting to see when the eco will finally be launched.
- Economists are debating whether the introduction of the eco will provide the necessary stability for regional trade in West Africa.

Usage: Usually capitalized in formal economic reports, though often lowercase in general news.

## Examples

- We should buy more eco products for our home.
- The city is investing in eco friendly public transport to reduce carbon emissions in the downtown area.
- While the company markets itself as an eco alternative, critics argue that its manufacturing process remains significantly more carbon-intensive than its branding suggests.

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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.