Definition List: Definition

Definition, explanation, or expansion of a word, phrase, or abbreviation.


This element is used in two contexts:

  1. Within a two-part list (<def-list>), <def> contains the definition or description of a word or phrase. In this usage, <def> is half of a <term>/<def> pair within an item (<def-item>) in the definition list.
    The term <term> part of a definition item may be a term, a word, a phrase, a picture or icon, an equation, a variable, or anything else that is to be explained. The definition <def> part of an item in a two-part (definition) list need not be a “definition” in the strict dictionary sense of that word. Such a definition could be a discussion, explanation, expansion, or just a few words that tell the reader about the <term>. When a <def-list> is within a <glossary> element, the definitions are assumed to be real definitions.
  2. Within an <abbrev> element, <def> contains the definition or expansion of an abbreviation, acronym, or emoticon (“;-)”).


id Identifier
rid Reference to an Identifier
specific-use Specific Use
xml:lang Language

Related Elements

A <def-list> may take a <label> that provides it with a number or other designator, followed by an optional <title> naming the entire list, followed by optional headings for terms and their definitions. <term-head> contains the heading over the first (term) column, and <def-head> contains the heading for the second (definition) column; neither serves as a container element for terms or definitions. Individual <term>s and their <def>s are paired in <def-item>s. Definition lists are recursive, so following all the terms and definitions, there may be one or more embedded <def-list> elements.

Content Model

<!ELEMENT  def          %def-model;                                  >

Expanded Content Model



Any one of:

This element may be contained in:

<abbrev>, <def-item>


<def-item><term id="G1">PAP I</term>
<def><p>poly(A)polymerase I</p></def>
<def-item><term id="G2">PNPase</term>
<def><p>polynucleotide phosphorylase</p></def>