$result = mysql_query("SELECT word, definition FROM wordtable ORDER by word ASC"); 

$wordlist = array();

while($row = mysql_fetch_row($result)
  $wordlist[$row[0]] = $row[1];

foreach ($wordlist as $word => $defintion)
{
  echo "<a name=\"$word\">$word</a>";
  $definition_words = explode($definition, ' ');
  
  foreach($definition_words as $this_word)
  {
    if ( isset($wordlist[$this_word]) )
      echo "<a href=\"#{$this_word}\">$this_word ";
    else
      echo "$this_word ";
  }
  echo '<hr>';
}