\documentclass{article}

\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage[portuguese]{babel}
\usepackage{glossaries}

\makeglossaries

\newglossaryentry{tomorrow}{name={amanhã},description={tomorrow}}

\begin{document}
\gls{tomorrow}

\printglossary
\end{document}