source

source — noun

1. the starting point of something — for instance, where a river first rises, what

1.nounB1
Definition

the starting point of something — for instance, where a river first rises, what causes a problem, or who provides money or materials.

Example

The Yangtze River has its source in the glaciers of the Tibetan Plateau.

concrete: source of a river

Late nights at work were a constant source of stress for Layla.

abstract: source of [emotion/problem]

Common collocations
  • source of conflict
  • source of income
  • source of energy
  • source of inspiration
Synonyms
  • origin

    emphasises the starting point in time or space; 'origin of the custom' vs 'source of the river'

  • root

    suggests a deep, underlying cause, especially of a problem

  • cause

    focuses on the reason something happens, not on where it begins

Antonyms
  • result

    what comes out of something rather than what starts it

  • outcome

    the final effect, not the starting point

Grammar Patterns

the source of [something]

a source of [noun phrase]

Usage Note

The noun that follows 'source of' can be either positive (a source of joy, a source of inspiration) or negative (a source of trouble, a source of conflict).

Common Mistakes

The source the problem is unknown.
The source of the problem is unknown.
'source' requires the preposition 'of' when naming what comes from it.

2. a person, document, website, or organization that gives you facts, news, or data

2.nounB1
Definition

a person, document, website, or organization that gives you facts, news, or data that you can use or refer to.

Example

According to a reliable source inside the company, layoffs are expected next month.

collocation: reliable source

Reema listed all her sources at the end of her research paper.

academic: list one's sources

Common collocations
  • reliable source
  • anonymous source
  • primary source
  • source material
  • source text
Synonyms
  • reference

    a specific work (book, article) cited in academic writing

  • informant

    a person who gives information, often secretly

  • authority

    an expert or reliable work on a subject

Grammar Patterns

[adjective] source

source of [information/news/data]

from a reliable source

Usage Note

Common adjectives with this sense: 'reliable', 'anonymous', 'unidentified', 'trusted', 'primary'. In journalism, 'sources' often refers to people who give information on condition of anonymity.

Common Mistakes

He is a good source information.
He is a good source of information.
even in this sense, 'source' needs 'of' before the kind of content.

3. at the original place or point where something starts, before it spreads, moves,

3.nounB2
Definition

at the original place or point where something starts, before it spreads, moves, or changes — used in the fixed phrase 'at source'.

Example

To prevent food poisoning, officials aim to stop contamination at source.

fixed phrase: at source

The government deducts income tax at source, before workers receive their pay.

Common collocations
  • at source
  • stop at source
  • tax at source
  • deal with at source
Antonyms
  • downstream

    later in a process, after something has already spread or been changed

Grammar Patterns

at source

Usage Note

This sense nearly always appears in the fixed phrase 'at source'. Unlike sense 1, you cannot say 'the source' here — 'at source' functions as an adverbial unit meaning 'before it spreads or is processed'.

Common Mistakes

The tax is deducted at the source.
The tax is deducted at source.
the definite article 'the' is not used in this fixed phrase.
Idioms

at source

idiom

At the place or point where something starts or comes from.

The company deducts income tax at source from each salary.

To reduce waste, we should stop it at source.

source — verb

Word family

  • sourcing
    nounC1
  • outsource
    verbC1
  • outsourcing
    nounC1

Synonym discussion

Sense: noun/1

All four words refer to where something starts, but they differ in focus. Source is the broadest: it can be the physical starting point of a river (the source of the Nile), the person or thing that provides something useful (a source of funding), or the reason behind a situation (a source of conflict). Origin points more narrowly to the earliest point in time or the place where something was created — the origin of a tradition, the origin of a species. Root suggests a deep, fundamental cause, usually of something negative — the root of the problem, the root of all evil. Cause is the most direct: it names the person, event, or condition that makes something happen — the cause of the accident, the cause of the fire. If you are looking for the basic starting point, use source or origin. If you want to emphasise a deep underlying reason, use root. If you need to name what directly produces an effect, use cause.

origin ↗root ↗source ↗cause ↗

Common collocations

Nouns

  • source code
  • source material
  • source text

Adverbs

  • directly sourced
  • ethically sourced
  • locally sourced
  • responsibly sourced

Phrases

Prepositions

Etymology

LatinOld FrenchEnglish

The word 'source' comes from Old French 'sourse' (meaning a rising up or a spring of water), which in turn came from the Latin verb 'surgere' (to rise or spring up). The original meaning referred to the spring where a river begins. By the 14th century, it had broadened to mean any starting point, and later came to refer to providers of information and evidence.