dioxide

IPA/daɪˈɒksaɪd/
KK[daɪˈɑksˌaɪd]IPA/daɪˈɑːksaɪd/

dioxide — noun

1. a chemical that forms when one atom of a non-oxygen element joins together with

1.nounB2
Definition

a chemical that forms when one atom of a non-oxygen element joins together with a pair of oxygen atoms

Example

Dr. Tariro checked the carbon dioxide reading before opening the storage tank.

compound name: carbon dioxide

Burning wood produces carbon dioxide as a natural byproduct of the reaction.

verb collocation: produce + dioxide

Common collocations
  • carbon dioxide
  • sulfur dioxide
  • nitrogen dioxide
  • chlorine dioxide
  • release dioxide
  • produce dioxide
  • dioxide level
  • dioxide emissions
  • atmospheric dioxide
Antonyms
  • monoxide

    a compound with only one oxygen atom instead of two, e.g. carbon monoxide (CO)

Grammar Patterns

dioxide + noun (e.g. dioxide levels)

compound_name like carbon dioxide

Usage Note

Dioxide is rarely used alone; it almost always appears as the second word in a compound name such as carbon dioxide, sulfur dioxide, or nitrogen dioxide. Carbon dioxide (CO₂) is by far the most common form in everyday language.

Common Mistakes

The lab measured the dioxide in the atmosphere.
The lab measured the carbon dioxide in the atmosphere.
Dioxide alone sounds incomplete; specify which dioxide (e.g., carbon dioxide, sulfur dioxide) in most contexts.
Carbon dioxide is an oxide with one oxygen atom.
Carbon dioxide is an oxide with two oxygen atoms.
The prefix di- means 'two' — confusing dioxide with monoxide changes the chemical meaning.

Word family

Synonym discussion

Sense: noun/1

Dioxide, oxide, and monoxide are related chemical terms that differ in the number of oxygen atoms. Oxide is the broadest term — any compound of oxygen with another element (e.g., iron oxide, magnesium oxide). Dioxide specifies exactly two oxygen atoms per molecule, as in carbon dioxide (CO₂). Monoxide specifies exactly one oxygen atom, as in carbon monoxide (CO). In everyday usage, people talk about 'carbon dioxide' far more often than the other two because of its role in climate change and respiration. An easy way to remember: the prefix di- means 'two' (like bicycle = two wheels), so dioxide = two oxygens; mon- means 'one' (like monorail = one rail), so monoxide = one oxygen.

dioxide ↗oxide ↗monoxide ↗

Common collocations

Nouns

Prepositions

Etymology

GreekFrenchEnglish

Dioxide was formed in the early 1800s by combining the prefix di- (from Greek, meaning 'two') with oxide, which itself comes from French oxyde. The term was created as chemists developed a clearer understanding of gas composition and needed precise names for molecules with different numbers of oxygen atoms.