diff --git a/README.markdown b/README.markdown
index c206dfb..add552e 100644
--- a/README.markdown
+++ b/README.markdown
@@ -71,6 +71,25 @@ See the [original README][] for details.
 [original README]: https://github.com/jgm/peg-markdown/blob/master/README.markdown
 [knieriem/peg]: https://github.com/knieriem/peg
 
+
+## Extensions
+
+In addition to the extensions already present in peg-markdown,
+this package also supports definition lists (option `-dlists`)
+similar to the way they are described in the documentation of
+[PHP Markdown Extra][].
+
+Definitions (`<dd>...</dd>`) are implemented using [ListTight][]
+and `ListLoose`, on which bullet lists and ordered lists are based
+already. If there is an empty line between the definition title and
+the first definition, a loose list is expected, a tight list otherwise.
+
+As definition item markers both `:` and `~` can be used.
+
+[PHP Markdown Extra]: http://michelf.com/projects/php-markdown/extra/#def-list
+[ListTight]: https://github.com/knieriem/markdown/blob/master/parser.leg#L191
+
+
 ## Todo
 
 *	Implement definition lists (work in progress), and perhaps tables
diff --git a/misc/func-name2line.rc b/misc/func-name2line.rc
new file mode 100644
index 0000000..8b58438
--- /dev/null
+++ b/misc/func-name2line.rc
@@ -0,0 +1,19 @@
+# print file and line number of closure func_$1
+
+fnid=$1
+pkg=markdown
+
+account=github.com/knieriem
+objpfx=$GOROOT/src/pkg/$account/+m/_obj
+prj=$account
+cmd=(info line $objpfx/$prj/$pkg._func_$fnid)
+cmd=`{echo $cmd | sed 's,\.com,%2ecom,g'}
+echo $cmd
+gdb --batch --eval-command $"cmd ./cmd/markdown >[2] /dev/null |
+	grep '^Line.*of' |
+	awk '
+	{
+		gsub("\"", "", $4)
+		print $4 ":" $2
+	}
+'
diff --git a/output.go b/output.go
index 7d33c5e..e8c7b17 100644
--- a/output.go
+++ b/output.go
@@ -199,6 +199,12 @@ func (w *htmlOut) elem(elt *element, obfuscate bool) *htmlOut {
 		w.pad(2).s("<ul>").pset(0).elist(elt.children, obfuscate).pad(1).s("</ul>").pset(0)
 	case ORDEREDLIST:
 		w.pad(2).s("<ol>").pset(0).elist(elt.children, obfuscate).pad(1).s("</ol>").pset(0)
+	case DEFINITIONLIST:
+		w.pad(2).s("<dl>").pset(0).elist(elt.children, obfuscate).pad(1).s("</dl>").pset(0)
+	case DEFTITLE:
+		w.pad(1).s("<dt>").pset(2).elist(elt.children, obfuscate).s("</dt>").pset(0)
+	case DEFDATA:
+		w.pad(1).s("<dd>").pset(2).elist(elt.children, obfuscate).s("</dd>").pset(0)
 	case LISTITEM:
 		w.pad(1).s("<li>").pset(2).elist(elt.children, obfuscate).s("</li>").pset(0)
 	case BLOCKQUOTE:
diff --git a/parser.leg b/parser.leg
index c045982..d4773e2 100644
--- a/parser.leg
+++ b/parser.leg
@@ -84,6 +84,9 @@ const (
 	HRULE
 	REFERENCE
 	NOTE
+	DEFINITIONLIST
+	DEFTITLE
+	DEFDATA
 	numVAL
 )
 
@@ -114,6 +117,7 @@ Block =     BlankLine*
             | Reference
             | HorizontalRule
             | Heading
+            | DefinitionList
             | OrderedList
             | BulletList
             | HtmlBlock
@@ -191,7 +195,7 @@ BulletList = &Bullet (ListTight | ListLoose)
 
 ListTight = a:StartList
             ( ListItem { a = cons($$, a) } )+
-            BlankLine* !(Bullet | Enumerator)
+            BlankLine* !(Bullet | Enumerator | DefMarker)
             { $$ = mk_list(LIST, a) }
 
 ListLoose = a:StartList
@@ -203,7 +207,7 @@ ListLoose = a:StartList
               } )+
             { $$ = mk_list(LIST, a) }
 
-ListItem =  ( Bullet | Enumerator )
+ListItem =  ( Bullet | Enumerator | DefMarker )
             a:StartList
             ListBlock { a = cons($$, a) }
             ( ListContinuationBlock { a = cons($$, a) } )*
@@ -235,7 +239,7 @@ Enumerator = NonindentSpace [0-9]+ '.' Spacechar+
 OrderedList = &Enumerator (ListTight | ListLoose)
               { $$.key = ORDEREDLIST }
 
-ListBlockLine = !( Indent? (Bullet | Enumerator) )
+ListBlockLine = !( (Indent? (Bullet | Enumerator)) | DefMarker )
                 !BlankLine
                 !HorizontalRule
                 OptionallyIndentedLine
@@ -744,6 +748,38 @@ RawNoteBlock =  a:StartList
                     $$.key = RAW
                 }
 
+
+DefinitionList = &{ p.extension.Dlists }
+			a:StartList
+			( Definition { a = cons($$, a) } )+ 
+			{ $$ = mk_list(DEFINITIONLIST, a) }
+
+Definition =	&( (!Defmark RawLine)+ BlankLine? Defmark)
+			a:StartList
+			( DListTitle { a = cons($$, a) } )+
+			( DefTight | DefLoose ) {
+				for e := $$.children; e != nil; e = e.next {
+					e.key = DEFDATA
+				}
+				a = cons($$, a)
+			}
+			{ $$ = mk_list(LIST, a) }
+
+DListTitle =	NonindentSpace !Defmark &Nonspacechar
+			a:StartList
+			(!Endline Inline { a = cons($$, a) } )+
+			Sp Newline
+			{	$$ = mk_list(LIST, a)
+				$$.key = DEFTITLE
+			}
+
+DefTight	= &Defmark ListTight
+DefLoose	= BlankLine &Defmark ListLoose
+
+Defmark	= NonindentSpace (':' | '~') Spacechar+
+DefMarker	= &{ p.extension.Dlists } Defmark
+
+
 %%
 
 
@@ -963,4 +999,7 @@ var keynames = [numVAL]string{
 	HRULE:			"HRULE",
 	REFERENCE:		"REFERENCE",
 	NOTE:			"NOTE",
+	DEFINITIONLIST:	"DEFINITIONLIST",
+	DEFTITLE:		"DEFTITLE",
+	DEFDATA:		"DEFDATA",
 }