[Jcbones]

With a lot of bad words, this function can get consuming, but it does filter whole words only, and will not split words up.

Using wirehoppers example, with a litte changing around.

PHP Code:

<?php
/* Read in from the file here, not in the function - you only need to read the file once */
$wordlist[] = 'one';
$wordlist[] = 'two';
$wordlist[] = 'three';
$wordlist[] = 'four';

/* Sample data */
$words = 'stone twoot three fourth under oven tree cookie oneder ream one sixone threetwo fournine four';

foreach ($wordlist as $v)
      $words = clean($v,$words);

function clean($wordlist,$value)
{
        return preg_replace("/\b$wordlist\b/i", '***',trim($value));
}  

echo 'Words: '.$words.PHP_EOL;
?>

Code:

Words: stone twoot *** fourth under oven tree cookie oneder ream *** sixone threetwo fournine ***