function replace_text_wps($text){
$replace = array(
'wordpress' => '<b>wordpress</b>',
);
$text = str_replace(array_keys($replace), $replace, $text);
return $text;
}

add_filter('the_content', 'replace_text_wps');
add_filter('the_excerpt', 'replace_text_wps');

Functions.php ekleyin