\documentclass{article}

\pagestyle{empty}

\newcommand{\A}{abc}

\begin{document}

Hello World

A

\A abc\A

Taumatawhakatangihangakoauauotamateaturipukakapikimaungahoronukupokaiwhenuakitanatahu

First footnote\footnote{I am a footnote!}.

A much longer and more evil second footnote\footnote{A much longer and more evil second footnote}.

\section{ABC}

\section{section}

\end{document}