I'm using the enumitem package, and am having trouble setting the horizontal spacing parameters (leftmargin,itemindent,labelsep,labelindent,labelwidth) so as to get the following effect:
LabelGoesHere The quick brown fox jumped over the lazy dog. The
quick brown fox jumped over the lazy dog. The quick
brown fox jumped over the lazy dog. The quick brown
fox jumped over the lazy dog.
that is, both the first line (not including the label) and the other lines start at the same point. For the lines other than the first, this works fine (for alignment at 2cm from the margin):
\begin{description}[
leftmargin=2cm,
itemindent=0cm
]
but the first line is giving me trouble. Am I supposed to use the label's width somehow? Should I use ! or * ?
PS - Bonus points if you could help me make the distance from the start of the line at which alignment happens be the maximum necessary to fit all of the item labels used in the list, plus some fixed amount of clearance.

\item[LabelGoesHere] The quick brown fox...\end{description}? – einpoklum Jul 02 '17 at 19:54\documentclassand ending with\end{document}. – cfr Jul 02 '17 at 20:01