-\def\note{\@ifnextchar[\note@i{\note@i[Note]}}
-\def\note@i[#1]{%
- \basedescript{%
- \sbox\z@{\makelabel{#1}}%
- \desclabelwidth{\wd\z@}%
- }%
- \item[\box\z@]%
-}
-\let\endnote\endbasedescript
+\ifx\note\@@undefined
+ \def\note{\@ifnextchar[\note@i{\note@i[Note]}}
+ \def\note@i[#1]{%
+ \basedescript{%
+ \sbox\z@{\makelabel{#1}}%
+ \desclabelwidth{\wd\z@}%
+ }%
+ \item[\box\z@]%
+ }
+ \let\endnote\endbasedescript
+\fi