[OS X TeX] environment for symbol notation

[Themis Matsoukas]

I want to include in a paper a list of symbols that is formatted  
something like this:

$X$     long, windy and verbose  description that may span more
            than one line, but if does, it should be properly indented.

So far I've been doing this using

\makebox[50pt][l]{$X$} Short description

while keeping the descriptions short to avoid running into the next  
line.  Is there a better way?

Themis Matsoukas