This seems to be quite a common question with ordinary tabular environments, but I have not been able to find an answer for this problem, or any like it, using the tabularx environment.
My code is as follows:
\begin{tabularx}{\textwidth}{|p{3cm}|X|}
\hline
\textbf{Symbol (Name)} & \textbf{Example of Use}\\
\hline
\multirow{2}{*}{symbol\newline (Full name))} & $x=\hdots$\\
\hline
& Description
\end{tabularx}
which produces:

I am trying to make (Full name)) appear on the line below symbol without the horizontal line extending all the way to the left. I only want to third horizontal line to separate the column on the right.
How do I achieve this with the tabularx environment?
With many thanks,
Froskoy.
