I would like to temporarily undefine a command. The reason for this is that I need to use a specific class file which defines the equation* using \@namedef and I would also really like to use the amsmath package as it in particular defines the align environment, but it also defines the equation* environment, so this leads to an error at compilation.
I have found how to temporarily disable a command without a star, i.e. by doing
\makeatletter \let\oldequation\equation \let\equation\@undefined \makeatother
and then loading the amsmath package.
This doesn't work for equation* for reasons I don't quite understand, but apparently * at the end starts a new lexeme.
So how would I achieve a similar result for equation*? The class and style files are not under my control.