Home / Glossary / Defamation Law
Glossary

Defamation Law glossary

Defamation is governed by the uniform Defamation Acts enacted in each state and territory, most prominently the Defamation Act 2005 (NSW), substantially amended by the 2021 Stage 1 reforms. This glossary covers 40 of the most commonly used terms — from concerns notices and serious harm to defences and damages caps.

In short

This is a glossary of 40 key terms used in Australian defamation law. Each term has a plain-English definition and, where applicable, a reference to the uniform Defamation Acts or leading authority. Use it as a reference for advising publishers, complainants, and in litigation.

Use these terms with Quillio — free trial
40 terms

Definitions

Absolute privilege

A complete defence for statements made in parliamentary or judicial proceedings, regardless of malice or truth. Cannot be defeated.

Example: Statements made by a witness on the stand are absolutely privileged.

Defamation Act 2005 (NSW) s 27

Aggravated damages

Additional compensatory damages awarded where the defendant's conduct has increased the hurt to the plaintiff — for example, by failing to apologise or repeating the imputation.

Defamation Act 2005 (NSW) s 36

Cap on damages

The statutory maximum for non-economic loss in defamation, indexed annually. Only exceeded where aggravated damages are warranted following the 2021 reforms.

Defamation Act 2005 (NSW) s 35

Concerns notice

A written notice now mandatory before commencing defamation proceedings. Must specify the imputations and allow the publisher an offer to make amends period.

Defamation Act 2005 (NSW) s 12A

Contextual truth

A defence where imputations not complained of are substantially true and, because of their substantial truth, the imputations complained of do not further harm reputation.

Defamation Act 2005 (NSW) s 26

Defamatory imputation

The meaning conveyed by a publication that is capable of damaging reputation — lowering the plaintiff in the estimation of ordinary reasonable people.

Defamation Act 2005 (NSW)

Ephemeral publication

A publication with limited temporal reach (for example, a brief social media post). Relevant to assessing serious harm and damages quantum.

Fair comment (honest opinion)

A defence for statements of opinion (not fact) on matters of public interest, based on proper material, where the opinion is honestly held.

Defamation Act 2005 (NSW) s 31

General damages

Non-economic loss damages awarded for injury to reputation, hurt feelings, and vindication. Subject to the statutory cap.

Defamation Act 2005 (NSW) s 34

Grain of truth

Colloquial term for the evidentiary threshold required to sustain a justification defence — defendant must prove substantial truth of the imputation.

Identification

A pleaded element requiring the plaintiff to prove the defamatory matter was about them — whether by name, photograph, or reasonable inference.

Imputation

The specific defamatory meaning a plaintiff pleads as arising from the matter complained of. Each imputation must be pleaded with precision.

Example: The defendant published the false imputation that the plaintiff is a fraudster.

Defamation Act 2005 (NSW)

Injunction

Equitable relief restraining publication. Interlocutory injunctions in defamation are rarely granted because of the public interest in free speech.

Innocent dissemination

A defence for subordinate distributors (for example, news agents, ISPs) who neither knew nor ought to have known they were publishing defamatory matter.

Defamation Act 2005 (NSW) s 32

Internet intermediary

An online platform, search engine, or hosting service. Potentially liable as a publisher where it has notice and does not act.

Justification (truth)

The complete defence that the defamatory imputation is substantially true. A cornerstone defence under the uniform Acts.

Defamation Act 2005 (NSW) s 25

Limitation period

Defamation claims must generally be commenced within one year of publication, extendable in limited circumstances. Single publication rule applies post-2021.

Limitation Act 1969 (NSW) s 14B

Malice

Improper motive or knowledge of falsity. Defeats qualified privilege and honest opinion defences.

Matter of public interest

A topic whose publication concerns the public generally — essential threshold for the public interest defence and honest opinion.

Defamation Act 2005 (NSW) s 29A

Mitigation of damages

Factors reducing damages — for example, apologies, corrections, withdrawal, or prior damaged reputation.

Defamation Act 2005 (NSW) s 38

Offer to make amends

A written offer under Part 3 to publish a correction, apology, and pay reasonable expenses. A bar to proceedings if reasonable and not accepted.

Defamation Act 2005 (NSW) ss 13-19

Ordinary reasonable reader

The hypothetical reader through whose eyes the court determines whether a publication conveys a defamatory meaning.

Parliamentary privilege

The absolute privilege covering statements made in parliamentary proceedings. Extends to fair reports of those proceedings on a qualified basis.

Parliamentary Privileges Act 1987 (Cth)

Permanent injunction

A final order restraining future publication of defamatory matter. Granted sparingly at the end of proceedings.

Public interest defence

A defence introduced in the 2021 reforms where the defendant proves the matter concerns an issue of public interest and they reasonably believed publication was in the public interest.

Defamation Act 2005 (NSW) s 29A

Publication

The communication of defamatory matter to at least one person other than the plaintiff. A constitutive element of the cause of action.

Defamation Act 2005 (NSW)

Qualified privilege

A defence for publications made on occasions of shared duty or interest, or where the recipient had a reasonable interest in receiving the information.

Defamation Act 2005 (NSW) s 30

Rebuttable presumption of damage

Historical common law principle that damage was presumed on publication. Displaced in 2021 by the serious harm threshold.

Reply to attack

A form of qualified privilege protecting a person who responds proportionately to a public attack on their reputation.

Reputation

The estimation in which a person is held by others. The interest protected by defamation law.

Scientific or academic peer review

A defence for peer-reviewed publications on scientific or academic matters, where an independent review panel assessed the publication's merits.

Defamation Act 2005 (NSW) s 30A

Serious harm

The statutory threshold introduced in 2021 — the plaintiff must prove the publication has caused, or is likely to cause, serious harm to reputation.

Defamation Act 2005 (NSW) s 10A

Single publication rule

A rule treating a continuous online publication as first published on the date first uploaded for limitation purposes, introduced in 2021.

Limitation Act 1969 (NSW) s 14B

Sting of the imputation

The central defamatory meaning conveyed by a publication — the element that must be substantially proved true for the justification defence.

Subordinate distributor

A distributor (for example, a news agent or ISP) who is not the author, editor, or primary publisher. Key to the innocent dissemination defence.

Defamation Act 2005 (NSW) s 32

Substantial truth

The standard for the justification defence — the defendant must prove the sting of the imputation is true in substance, not every detail.

Defamation Act 2005 (NSW) s 25

Trivial defence

The former defence that the circumstances of publication were unlikely to cause harm. Largely supplanted by the serious harm threshold in 2021.

Voller (liability of page operators)

Following Fairfax v Voller [2021] HCA 27, operators of social media pages can be publishers of third-party comments on their posts.

Fairfax Media Publications Pty Ltd v Voller [2021] HCA 27

Without prejudice correspondence

Communications made in a genuine attempt to settle a dispute. Generally inadmissible in evidence, but offers to make amends have specific statutory treatment.

Use with Quillio

Research these terms in context

Quillio is purpose-built for Australian defamation practitioners. Use it to research these terms against current uniform Defamation Act authority and the 2021 reforms. See /practice-areas/litigation-lawyers or start a free trial.

These definitions are general explanations for educational purposes — not legal advice. Always verify against current legislation and case law before relying on them in a client matter.

Research these terms with citations.

Quillio gives you the term, the current authority, and a clickable citation — all in one place. The free trial requires no credit card and no sales call.

Start your free trial