\documentclass{article}% code by Donald Arseneau
\usepackage{ulem}
\usepackage{color}
\parindent=0pt
\makeatletter
\def\brokenuline{\bgroup
 \UL@pixel.3\p@ \ULdepth .25ex
 \let\UL@putbox\UL@brokenputbox \ULset}

\def\UL@brokenputbox{\ifx\UL@start\@empty \else % not inner
  \vrule\@width\z@ \LA@penalty\@M
  {\UL@skip\wd\UL@box \advance\UL@skip\UL@pixel \UL@leaders \kern-\UL@skip}%
  \textcolor{white}{%
   \kern-2\UL@pixel\copy\UL@box\kern-\wd\UL@box
   \kern  \UL@pixel\raise.4\p@\copy\UL@box\kern-\wd\UL@box
   \kern  \UL@pixel\lower.4\p@\copy\UL@box\kern-\wd\UL@box
   \kern  \UL@pixel\raise.4\p@\copy\UL@box\kern-\wd\UL@box
   \kern  \UL@pixel\copy\UL@box\kern-\wd\UL@box
   \kern-2\UL@pixel}\box\UL@box  \fi}

\makeatother

\begin{document}

Those \uline{Sloppy jazz grapes squint (while) pilfering.}

Those \brokenuline{Sloppy jazz grapes squint (while) pilfering.}

\begin{verbatim}
\usepackage{ulem}
\usepackage{color}
\parindent=0pt
\makeatletter
\def\brokenuline{\bgroup
 \UL@pixel.3\p@ \ULdepth .25ex
 \let\UL@putbox\UL@brokenputbox \ULset}

\def\UL@brokenputbox{\ifx\UL@start\@empty \else % not inner
  \vrule\@width\z@ \LA@penalty\@M
  {\UL@skip\wd\UL@box \advance\UL@skip\UL@pixel \UL@leaders \kern-\UL@skip}%
  \textcolor{white}{%
   \kern-2\UL@pixel\copy\UL@box\kern-\wd\UL@box
   \kern  \UL@pixel\raise.4\p@\copy\UL@box\kern-\wd\UL@box
   \kern  \UL@pixel\lower.4\p@\copy\UL@box\kern-\wd\UL@box
   \kern  \UL@pixel\raise.4\p@\copy\UL@box\kern-\wd\UL@box
   \kern  \UL@pixel\copy\UL@box\kern-\wd\UL@box
   \kern-2\UL@pixel}\box\UL@box  \fi}

\makeatother

Those \uline{Sloppy jazz grapes squint (while) pilfering.}

Those \brokenuline{Sloppy jazz grapes squint (while) pilfering.}
\end{verbatim}


\end{document} 