diff

diff — noun

1. the amount or way in which two or more things are not the same — a shortened, in

1.nounB1
Definition

the amount or way in which two or more things are not the same — a shortened, informal form of the word 'difference'.

Example

There is a noticeable diff between the summer and winter hotel rates.

diff + between + two things

Chiara could not see any diff between the two shades of blue paint.

Common collocations
  • big diff
  • small diff
  • price diff
  • age diff
  • time diff
  • see the diff
  • tell the diff
  • same diff
Synonyms
  • difference

    the full, neutral form suitable for all registers

  • gap

    emphasises a large or significant difference between positions or levels

  • disparity

    more formal; suggests an unfair or unequal difference

Antonyms
  • sameness

    the quality of being identical or very similar

  • similarity

    a point or way in which things are alike

Grammar Patterns

diff + between + plural noun phrase

Usage Note

Frequently used in fixed phrases such as 'what's the diff?' and 'same diff'. Avoid this short form in formal academic or business writing.

Common Mistakes

Can you diff the two items?
Can you see the diff between the two items?
'diff' is a noun, not a verb; the verb form is 'differ'.

2. in computing, a tool or command that compares two text files and shows which lin

2.nounB2
Definition

in computing, a tool or command that compares two text files and shows which lines differ; the report produced by that tool is also called a diff.

Example

Nila ran a diff on the two versions of the configuration file.

collocation: run a diff + on [file]

When Liam compared the two website files, the diff tool highlighted every line that had changed.

Common collocations
  • run a diff
  • diff tool
  • diff output
  • diff report
  • check the diff
  • diff against
Synonyms
  • comparison

    a general term; less technical than 'diff'

  • delta

    jargon for the set of changes between two versions

Grammar Patterns

run + diff

diff + between + noun phrase

Usage Note

Often used as a proper noun ('diff') to refer to the standard Unix comparison utility. The output of the tool can also be called a diff.

Common Mistakes

I diffed the files and they are the same.
I ran a diff on the files and they are the same.
'diff' is not commonly used as a verb in standard English; use 'run a diff' or 'compare'.

3. a shortened, informal name for the differential gear — the part of a vehicle tha

3.nounC1
Definition

a shortened, informal name for the differential gear — the part of a vehicle that lets the wheels on the same axle turn at different speeds when going around corners.

Example

The mechanic said the rear diff was leaking oil and would need to be repaired soon.

collocation: rear diff / front diff

A damaged diff can make a grinding noise when the car turns a corner.

Common collocations
  • rear diff
  • front diff
  • diff oil
  • diff housing
  • replace the diff
  • diff bearing
Synonyms

Usage Note

Common in automotive repair contexts and among car enthusiasts. Always refers to the differential — not the gearbox or transmission.

Common Mistakes

The diff needs new engine oil.
The diff needs new gear oil.
differentials use specialised gear oil, not standard engine oil.

diff — adjective

Word family

Synonym discussion

Sense: noun/1

All four words describe how things are not the same, but they differ in formality and emphasis. 'Diff' is the informal clipped form of 'difference', common in everyday speech ('What's the diff?') but unsuitable for formal writing. 'Difference' is the neutral, all-purpose term for any degree of unlikeness. 'Gap' suggests a large or significant separation, often in measurable quantities like wealth or scores ('a widening gap between rich and poor'). 'Disparity' is the most formal and implies an unfair or undesirable inequality, used in academic or journalistic contexts ('disparity in healthcare access'). For casual conversation, 'diff' or 'difference' works best; for analysis, choose 'gap' or 'disparity' depending on whether you want to emphasise size or injustice.

diff ↗difference ↗gap ↗disparity

Common collocations

Phrases

  • what's the diff?
  • same diff

Prepositions

Etymology

LatinFrenchEnglish

'Diff' is a shortened form created by clipping the beginnings of several longer words, most commonly 'difference' (from Latin 'differentia', meaning 'a carrying apart') and 'different' (from Latin 'differens', 'carrying apart'). The computing sense comes from the Unix 'diff' command, first released in the early 1970s by Douglas McIlroy at Bell Labs. The automotive sense is a clipping of 'differential gear', which itself derives from the mathematical concept of a differential (Latin 'differentialis', 'pertaining to a difference'). These clippings entered informal English through casual speech, technical jargon, and text messaging throughout the 20th and 21st centuries.