If you mean consecutive words, then use something like the following:

$word = qr{ \w [\w'-]* }x;
$nonword = qr{ [^\w'-]+ }x;
$text =~ s{
  \b
  ($word)
  (?: $nonword \1 )+
  (?! \w )  # UPDATE
}{$1}xg;
[download]

Very simply, it finds a word followed by some non-word thing, followed by the same word (one or more times), and replaces it with the original word.

_____________________________________________________
Jeff[japhy]Pinyan: Perl, regex, and perl hacker.
s++=END;++y(;-P)}y js++=;shajsj<++y(p-q)}?print:??;