The empty lines (or <tt>\par</tt>) after each description
(here notation) seem to be are necessary.
<b>Hint:</b> This solution uses the <tt>distance=</tt><i>dimension</i>
distance for separation of label and text. I could not find asolution yet, which aligns the text in the first line <b>Description with that of the other lines, if the minimal label width:</b> LaTeX:<small><pre>\documentclass{article}\usepackage{mdwlist}\begin{document}\begin{basedescript}{\desclabelstyle{\pushlabel}\desclabelwidth{6em}}\item[Label] bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla\item[Very long label is short enough.] bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla\end{basedescript}\end{document}</pre></small> ConTeXt: ???