Definitions

A definition provides the essential characteristics that distinguish a concept from other concepts. ISO 704:2022 §6 distinguishes four writing strategies and three anti-patterns. Glossarist v3.3 added a type field to DetailedDefinition covering all four strategies.

The four definition types (ISO 704:2022 §6.4)

Glossarist’s DetailedDefinition.type discriminator:

When type is omitted, the definition is treated as intensional — no migration needed for existing data.

Intensional definitions (§6.4.3)

The default and preferred form. An intensional definition begins by stating the immediate (closest) superordinate concept, followed by the delimiting characteristic(s).

definitions:
  - type: intensional
    content: >
      A pointing device that detects movement by means of rollers
      and light sensors, for controlling the location of a pointer
      on a computer screen.
    # Superordinate: "pointing device"
    # Delimiting characteristics: "detects movement by means of rollers and light sensors"
    # Domain qualifier: "for controlling the location of a pointer on a computer screen"

ISO 704 §6.4.3 lays down ten writing rules. The load-bearing ones for Glossarist adopters:

Extensional definitions (§6.4.5)

Enumerate the immediate subordinate concepts. ISO 704 is strict: extensional definitions are useful only in very limited circumstances and shall be used only if all three conditions hold:

1. The number of subordinate concepts is finite
2. The list is complete under one criterion of subdivision
3. Each subordinate is clarified by its own intensional definition OR is well-known

definitions:
  - type: extensional
    content: >
      A pointing device category comprising mechanical mice,
      optomechanical mice, and optical mice.

If any of the three conditions fails, write an intensional definition instead.

Partitive definitions

List the parts that constitute the whole. Often paired with a PartitiveHyperedge — the definition summarizes the rake for the entry’s narrative, the hyperedge carries the structured per-part data.

definitions:
  - type: partitive
    content: >
      Composed of a mouse ball, two rollers (x-axis, y-axis),
      an infrared emitter, an infrared sensor, a circuit board,
      a mouse button, and (optionally) a mouse wheel.

partitive_relations:
  # See /model/partitive-relations for the structured rake

Translated definitions (Glossarist extension)

Marks a definition that has been translated from another language’s definition rather than authored natively. Useful for tracking provenance in multi-language datasets where the original meaning must be preserved across translation.

definitions:
  - type: translated
    content: "A measurement result is composed of a measured quantity value and a measurement uncertainty."
    authoritative_source:
      ref: { source: VIM, id: "112-02-09" }
      lineage: "translated from eng → fra by AFNOR, 2024-03-12"

Deficient definitions to avoid (§6.5)

ISO 704 §6.5 names three anti-patterns. They are not separate type values — they are bugs to catch in review.

Circular definitions (§6.5.2)

A concept defined using a second concept, where the second is defined using the first. Two flavors:

• Inner circle — the designation is repeated in the definition (“tree height: tree height measured from…”)
• Outer circle — two concepts defined in terms of each other (“virgin forest: forest of natural tree stand” / “natural tree stand: stand in virgin forest”)

The substitution principle (§6.4.4) exposes outer circles: substitute the designation with its definition; if the result is recursive or tautological, the definition is circular.

Inaccurate definitions (§6.5.3)

A definition that is too broad (includes objects that shouldn’t be) or too narrow (excludes objects that should be). Usually caused by including non-delimiting or irrelevant characteristics.

Negative definitions (§6.5.4)

A definition that describes what a concept is not, rather than what it is. Permitted only when the concept is inherently negative (e.g. “infinity: a value that is not finite”).

YAML authoring

termid: "112-02-09"
status: valid
localizations:
  eng:
    terms:
      - type: expression
        designation: measurement result
        normative_status: preferred
    definition:
      - type: intensional
        content: >
          A set of quantity values being attributed to a measurand
          together with any other available relevant information.
        sources:
          - type: authoritative
            origin:
              ref: { source: VIM, id: "112-02-09" }

Multiple definitions are permitted (e.g. an intensional primary + a partitive supplementary):

definition:
  - type: intensional
    content: "A pointing device comprising…"
  - type: partitive
    content: "Composed of a mouse ball, two rollers, …"

Validation

Glossarist does not (yet) auto-detect circular or inaccurate definitions — these require human review per ISO 704 §6.4.4 (substitution principle). What is validated:

• type, when present, must be one of intensional | extensional | partitive | translated
• content must be non-empty
• sources, when present, must follow the ConceptSource shape

Future validator work: detect inner-circle circularity (designation repeated as the definition’s opening phrase); flag negative patterns (“not”, “without”) for reviewer attention; flag extensional definitions whose enumerated count doesn’t match the corresponding *Hyperedge member count.

See also

• Concepts — LocalizedConcept.definition field
• Concept System Types — how definitions fit into the larger concept system
• Sources — ConceptSource for definition provenance
• ISO 704:2022 §6 — writing and validating definitions
• ISO 10241-1 §6.4 — definition data category requirements