monoxide

monoxide — noun

1. the dangerous gas called carbon monoxide, often made when fuel burns without eno

1.nounC1
Definition

the dangerous gas called carbon monoxide, often made when fuel burns without enough air

Example

The carbon monoxide alarm rang after Gabriel started the car indoors.

collocation: carbon monoxide alarm

A cracked heater sent carbon monoxide through the flat overnight.

faulty heater releasing carbon monoxide

Common collocations
  • carbon monoxide detector
  • carbon monoxide alarm
  • carbon monoxide leak
  • monoxide poisoning
Synonyms
  • carbon monoxide

    The full and far more common everyday name for this gas.

  • CO

    The chemical formula, common on safety signs and technical labels.

Grammar Patterns

carbon monoxide detector

monoxide leak

monoxide poisoning

Usage Note

In everyday English, people usually say carbon monoxide rather than monoxide by itself. Common nearby words include detector, alarm, leak, and poisoning.

Common Mistakes

You can smell monoxide in the garage.
You can smell exhaust fumes, but carbon monoxide itself has no smell.
The gas is odourless, so the smell comes from other gases around it.
The room was full of monoxides.
The room was full of carbon monoxide.
When talking about poisoning risk, the gas is usually treated as uncountable.

2. a type of oxide that has only one oxygen atom in each molecule

2.nounC2
Definition

a type of oxide that has only one oxygen atom in each molecule

Example

Chemists call CO a monoxide because each molecule has one oxygen.

pattern: call X a monoxide

The textbook contrasts a monoxide with a dioxide in the next chapter.

contrast with dioxide

Common collocations
  • metal monoxide
  • monoxide molecule
  • monoxide formula
  • silicon monoxide
Synonyms
  • oxide

    A broader chemistry term for any compound containing oxygen, not just this one-oxygen type.

  • mono-oxide

    An older or less common spelling seen in some technical writing.

Grammar Patterns

a monoxide with one oxygen atom

metal monoxide

monoxide formula

Usage Note

Used mainly in chemistry writing and often contrasted with dioxide or trioxide. It usually appears after the name of the other element or compound, as in carbon monoxide.

Common Mistakes

A monoxide has two oxygen atoms.
A monoxide has one oxygen atom in each molecule.
The prefix mono- means one.

Synonym discussion

Sense: noun/1

In everyday safety warnings, monoxide almost always means carbon monoxide, the specific poisonous gas that can build up when fuel burns badly. CO is simply the chemical formula, so it appears more often on alarms, charts, or technical instructions than in ordinary conversation. Exhaust fumes are broader: they are the whole mix of gases and particles coming from an engine, and carbon monoxide is only one part of that mix. Smoke is different again because it is the visible dirty cloud from burning, while carbon monoxide itself cannot be seen. Say carbon monoxide or CO when the exact gas matters, but use exhaust fumes or smoke when you mean the wider dirty air around the fire or engine.

carbon monoxideCO ↗exhaust fumessmoke ↗

Etymology

GreekEnglish

Monoxide was formed in scientific English from mono-, from Greek monos meaning one, and oxide. The name describes a compound that contains a single oxygen atom, and carbon monoxide became the best-known everyday example of the term.