Definition List: Definition


Used in two senses:

  1. As the definition, description, or other explanation of a word, phrase, or picture in a two-part list, which is called a definition list.(The <def> element is part of a <term>/<def> pair within a <def-item>.); and
  2. As the definition or expansion of an abbreviation or acronym <abbrev> within an abbreviation <abbrev> element


The term <term> part of an item in a two-part (definition) list 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.


id Identifier
rid Reference to an Identifier

Related Elements

A Definition List may have a 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.

Model Information

Content Model

<!ELEMENT  def          %def-model;                                  >


Any one of:

This element may be contained in:

<abbrev> Abbreviation or Acronym; <def-item> Definition List: Definition Item

Tagged Example

<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>