hyphenate long underlined line

[hai...@histomat.net]

I have a long underlined glossary term that extends into the margin. Ulem package not helping. This is an example

\documentclass[12pt]{memoir}
\usepackage{ulem}
\usepackage[hidelinks]{hyperref}
   \hypersetup{
     linktocpage=true,
     colorlinks=false,
     linkcolor={false},
     unicode=true,
     pageanchor=true
     }
\usepackage[toc,nogroupskip]{glossaries}
\makeglossaries
\renewenvironment{theglossary}% needed in additon to nogorupskip option
   {\begin{list}{}
      {%
       \setlength\labelwidth{0pt}%
        \setlength\itemindent{-\leftmargin}%
       \setlength\itemsep{0pt}%
       \setlength\parsep{0pt}%
        \let\makelabel\descriptionlabel}%
       }
   {\end{list}}
\renewcommand*{\glstextformat}{\emph}

\newglossaryentry{primary and secondary formations}{
  name= primary and secondary formations,
  description={A unity fo two formations.}
}
\begin{document}

In the case of history we speak of the theory as a theory of
\gls{primary and secondary formations}. This term points to the unity
of two formations if indeed those formations actually exist.

\printglossaries

\end{document}