defstring – Define macros as verbatim macros
The command \defstring defines its first argument (a control sequence name) as the content of its second argument, with category code ‘other’, with surrounding braces added.
Maybe you are interested in the following packages as well.
- unouter: Suppress \outer flags in Plain TeX
- optparams: Macros with multiple optional parameters
- xoptarg: Expandable macros that take an optional argument
- mathcommand: \newcommand-like commands for defining math macros