null

null — adjective

1. not recognized or accepted by the law because it fails to meet legal requirement

1.adjectiveB2
Definition

not recognized or accepted by the law because it fails to meet legal requirements

Example

The court declared the old contract null because it was signed under pressure.

passive: declared + noun + null

After the merger, several clauses in the agreement became null and void.

collocation: null and void

Common collocations
  • null and void
  • declare null
  • rendered null
  • become null
Synonyms
  • void

    the most common synonym, often used together in 'null and void'

  • invalid

    slightly broader; can refer to any rule or argument that is not valid, not just legal documents

Antonyms
  • valid

    having full legal force

Grammar Patterns

be + null

declare + noun + null

Usage Note

Often paired with 'void' in the fixed phrase 'null and void', a legal formula that reinforces the meaning. Subject is typically a document, agreement, ruling, or legal act.

Common Mistakes

The contract is null and invalid.
The contract is null and void.
'null and void' is the standard legal phrase; 'invalid' is not used in this fixed expression.

2. producing no useful result or having no real importance

2.adjectiveB2
Definition

producing no useful result or having no real importance

Example

Without proper funding, all our planning efforts are effectively null.

adverb + null: effectively null

Élise felt that her years of training were null once she lost the championship.

Common collocations
  • prove null
  • become null
  • render null
  • effectively null
Synonyms
  • worthless

    more common in everyday speech for things of no material or practical value

  • meaningless

    focuses on lack of purpose or significance rather than outcome

  • futile

    emphasises that an attempt produced no result despite effort

Antonyms

Grammar Patterns

be + null

Usage Note

Frequently used with verbs like 'prove', 'become', 'render', or 'turn out to be'. Common in figurative contexts where effort, promise, or value is negated.

Common Mistakes

This computer is null.
This computer is worthless.
'null' is not used for physical objects that lack value; use 'worthless' or 'useless' instead.

3. in mathematics or computing, containing no members or consisting entirely of zer

3.adjectiveB2
Definition

in mathematics or computing, containing no members or consisting entirely of zeros

Example

João noticed that the spreadsheet tracking the closed project was a null matrix, with every entry set to zero.

attributive: null + noun (null matrix)

The database returned a null result when Takeshi searched for that product.

Common collocations
  • null matrix
  • null set
  • null value
  • null pointer
  • null result
Synonyms
  • zero

    interchangeable in mathematical contexts like 'null matrix' or 'zero matrix'

  • empty

    used for sets with no members; more intuitive for learners

Antonyms
  • non-null

    in computing, a value that exists and is not empty

Grammar Patterns

null + noun

be + null

Usage Note

Distinguish from sense 2 (worthless/meaningless): this sense is purely technical and describes the mathematical property of emptiness or zero. In computing, 'null' often refers to a pointer or value that points to nothing.

Common Mistakes

The box is null.
The box is empty.
'null' is not used for physical containers; use 'empty' for literal emptiness.
Idioms

null and void

idiom

Something that is no longer legally effective or acceptable.

The court ruled that the old contract was null and void.

If you break the rules, your ticket becomes null and void.

null — noun

null — verb

Word family

  • nullify
    verbB2
  • nullification
    nounC1
  • nullity
    nounC1
  • null and void
    adjective phraseB2

Synonym discussion

Sense: adjective/1

'Void' and 'null' are the closest synonyms in legal contexts, often used together in the fixed phrase 'null and void'. 'Void' alone means that something is completely empty of legal effect from the start, whereas 'invalid' covers any failure to meet legal standards, including procedural mistakes. 'Nullified' is the past participle of the verb 'nullify' and describes the result of an action that made something void — for example, a court ruling that nullified the contract. In everyday legal writing, 'null and void' is the safest and most idiomatic choice; 'invalid' sounds slightly more technical and is sometimes used for arguments or claims rather than documents.

void ↗invalid ↗null and void ↗nullified

Common collocations

Nouns

Adverbs

  • effectively null
  • legally null
  • completely null
  • declared null

Phrases

Etymology

LatinFrenchEnglish

The word 'null' comes from Latin 'nullus' meaning 'not any, none', formed from 'ne-' (not) and 'ullus' (any). It entered English in the 15th century through Old French 'nul' and Anglo-Norman legal usage, where it described documents with no legal force. The mathematical sense (null set, null matrix) developed in the 19th century, followed by the computing sense in the mid-20th century.