$re = '/(?!size)(?!resize)(?!Belize)(?!Bizet)(?!Brize)(?!Pfizer)(?!assize)(?!baize)(?!bedizen)(?!citizen)(?!denizen)(?!filesize)(?!maize)(?!prize)(?!netizen)(?!seize)(?!wizen)(?!outsize)(?!oversize)(?!misprize)(?!supersize)(?!undersize)(?!unsized)(?!upsize)(\w+)ize/m';
$str = 'Organize to socialize whatever size.';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php