10/03/2025

Interpreting and applying Legislation:

When might a statutory definition be more than just a definition? (Beware statutory definitions containing substantive material)

To avoid repetition and lengthy sections throughout a piece of legislation, drafters of statutes define frequently used terms, and list the definitions in their own separate section of the Act. Such sections may be headed ‘Definitions’, or ‘Interpretation’, or ‘Terms Used’, or ‘Dictionary’.

There is considerable law in Australia that guides how we interpret the meaning of a statute, including how we should use and interpret definitions.[1]

The function of a definition is to provide aid in construing a statute. The proper course, according to McHugh J in Kelly v R[2], is to “read the words of the definition into the substantive enactment and then construe the substantive enactment – in its extended or confined sense – in its context and bearing in bind its purpose and the mischief that it was designed to overcome.” McHugh J warned that “to construe the definition before its text has been inserted into the fabric of the substantive enactment invites error as to the meaning of the substantive enactment.” That ‘reading in’ of the words of a definition is referred to as the process of “substituting the definiens [i.e. the words or phrases comprising the definition] for the definiendum [i.e. the word or phrase defined]”.[3]

Sometimes, although a term may not be separately defined in a definition section, drafters use language to indicate that the words used in the statute have a particular scope. For example, a provision may set out factors that a decision maker is required to take into account when they are making a decision required under an Act. (Such an Act won’t always specify whether the list of factors is exhaustive, or whether the decision maker can also take into account other factors as well- that would be a matter of interpretation). The courts’ approach to interpreting definitions can also assist in the interpretation of such provisions.[4]

Ordinarily, “[t]he function of a definition clause in a statute is merely to indicate that when particular words or expressions the subject of a definition, are found in the substantive part of the statute under consideration, they are to be understood in the defined sense – or are taken to include certain things which, but for the definition, they would not include…”[5]

Complications in interpretation arise when definitions themselves are poorly drafted[6] and contain substantive material. Substantive provisions of a statute alter the substance of the law. For example, they might expressly state the rights or obligations of a person, or state conditions upon which an action can take place, and that action is recognised as one that can alter the rights or obligations of a person (such as making a will or holding a company meeting).[7]

In such circumstances, where a definition has the effect of altering the rights or obligations of people,[8] following the rule in Gibb’s Case will diminish its proper significance. Particularly where the definition in question applies in one section of the legislation only, and the construction of the definition as substantive material gives better effect to the policy of the Act,[9] courts should not be troubled by a departure from the usual way in which statutory definitions are construed.[10]

Footnotes

[1] For comprehensive instruction see DC Peace, Statutory Interpretation in Australia, 10th Ed 2024, Lexus Nexis (Pearce).

[2] Kelly v R [2004] HCA 12; (2004) 218 CLR 216 at [103]

[3] Campbell JA (Beazley and Ipp JJA agreeing) explained in San v Rumble (No. 2) [2007] NSWCA 259; cited in Pearce n 1 [6.3].

[4] Pearce (n 1) [6.16]

[5] Gibb v Federal Commissioner of Taxation [1966] HCA 64; (1966) 118 CLR 628 at 635 per Barwick CJ, McTiernan and Taylor JJ (Gibb’s Case).

[6] Pearce n 1 [6.22], quoted in Goldsmith v Law Complaints Officer [2021] WASC 69 at [53].

[7] San v Rumble (n 3) [42]

[8] San v Rumble (n 3) [53]

[9] As required in the interpretation of a statute by Project Blue Sky v Australian Broadcasting Authority [1998] 194 CLR 355.

[10] San v Rumble (n 3) [55]

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