HTML Tag: dfn
A definition — the defining instance of a term.
The paragraph, description list group, or section that the first instance of a specific dfn element appears in should also contain the definition of that term.
Optional Attributes
Example
<p><dfn><abbr title="HyperText Markup Language">HTML</abbr></dfn> is a computer language used to structure web-based content.</p>
<p>HTML <dfn>tags</dfn> mark the beginning and end of HTML elements.</p>