decomposition

decomposition — noun

1. the natural process by which dead plants, animals, or other organic material bre

1.nounB2
Definition

the natural process by which dead plants, animals, or other organic material breaks down and rots, helped by bacteria, fungi, and insects, eventually returning nutrients to the environment.

Example

The wet leaves in the garden showed clear signs of decomposition after days of rain.

collocation: signs of decomposition

Zayd turned the compost pile every week to speed up the decomposition of kitchen waste.

collocation: speed up decomposition

Common collocations
  • undergo decomposition
  • natural decomposition
  • decomposition process
  • signs of decomposition
  • speed up / slow down decomposition
  • rate of decomposition
  • decomposition of organic matter
  • bacterial / fungal decomposition
Synonyms
  • decay

    broader and more common in everyday English; 'decomposition' is preferred in formal or scientific writing

  • rotting

    more informal and specific to organic matter breaking down visibly; 'the rotting of the old fence'

  • putrefaction

    technical term especially for animal tissue decay; far less common in general use

Antonyms
  • growth

    decomposition breaks matter down; growth builds it up. 'The growth of new plants replaces what decomposition removes.'

  • preservation

    preventing decay. 'Freezing is a method of preservation that halts decomposition.'

Grammar Patterns

decomposition + of + organic matter

Usage Note

Commonly paired with 'undergo', 'speed up', and 'slow down'. Frequently modified by 'natural' and 'rapid'. This sense is the more common everyday meaning of the word.

Common Mistakes

The fruit underwent decomposition very quickly.
The fruit decayed very quickly.
For everyday situations about food going bad, 'decay' or 'rot' sound more natural than 'decomposition', which is formal or scientific in tone.
The smell came from the decomposition.
The smell came from the decomposing material.
'Decomposition' names a process, not a physical thing; use 'decomposing material' for the source of the smell.

2. the chemical process in which a compound splits apart to form simpler materials,

2.nounB2
Definition

the chemical process in which a compound splits apart to form simpler materials, typically through heating, electrolysis, or exposure to light.

Example

Strong heating causes the decomposition of calcium carbonate into lime and carbon dioxide.

thermal decomposition of calcium carbonate

Élise measured the rate of decomposition of hydrogen peroxide during the school chemistry lab.

collocation: rate of decomposition (chemistry)

Common collocations
  • chemical decomposition
  • thermal decomposition
  • electrolytic decomposition
  • decomposition reaction
  • decomposition of a substance
  • decomposition into simpler substances
  • catalytic decomposition
  • undergo decomposition
Synonyms
  • breakdown

    less technical and more general; 'the breakdown of hydrogen peroxide' is natural in both everyday and scientific English

  • splitting

    simpler and more informal; best for explaining the idea to beginners: 'splitting water into hydrogen and oxygen'

  • separation

    broader — covers physical as well as chemical separation; less precise for chemical reactions

Antonyms
  • synthesis

    the opposite chemical process: building larger molecules from smaller ones. 'Photosynthesis involves the synthesis of glucose from carbon dioxide and water.'

  • combination

    general opposite of separation; 'the combination of hydrogen and oxygen produces water'

Grammar Patterns

decomposition + of + substance + into + simpler substances

Usage Note

Subject is often a cause such as heat, light, or electricity. Frequently appears with the modifiers 'chemical', 'thermal', and 'catalytic'. Distinguish from sense 1: this sense describes a chemical reaction, not natural decay of living matter.

Common Mistakes

The chemical decomposition broke the salt into sodium and chlorine.
Chemical decomposition breaks salt down into sodium and chlorine.
Use 'break down' (phrasal verb) rather than 'broke' to describe a general chemical process, not a single past event.

Word family

  • decompose
    verbB2
  • decomposer
    nounB2
  • decomposable
    adjectiveC1
  • decomposed
    adjectiveB2

Synonym discussion

Sense: noun/1

All four describe the breakdown of organic matter, but they differ in formality and scope. 'Decay' is the most general and widely used word — it applies to teeth, food, wood, and even abstract structures ('urban decay'). 'Decomposition' is more formal and scientific, preferred in biology textbooks and laboratory reports. 'Rotting' is the most informal and concrete, often describing something visibly falling apart with a bad smell ('a rotting fence', 'rotting fruit'). 'Putrefaction' is a technical term restricted to the decomposition of animal tissue by bacteria, usually in forensic or medical contexts. In everyday conversation, 'decay' and 'rotting' are natural choices; in a biology exam, 'decomposition' is the expected term.

decompositiondecayrottingputrefaction

Common collocations

Nouns

  • process
  • rate
  • product
  • stage

Adverbs

  • quickly
  • slowly
  • rapidly

Phrases

  • undergo decomposition
  • the decomposition of something into something else
  • the rate of decomposition

Prepositions

  • into
  • by
  • of

Etymology

LatinFrenchEnglish

From Latin 'de-' (down, away) + 'componere' (to put together), via Old French 'decomposition'. The word literally means 'a taking apart of what was put together' — which matches both the biological and chemical senses. First recorded in English in the early 1600s in alchemy contexts, later adopted by biology and chemistry.