PHP replace content in a string
$item['menu_3'] = str_ireplace("T Shirts Vests", "TShirts", $item['menu_3']);

$item['menu_3'] = str_ireplace("T Shirts Vests","TShirts Vests", $item['menu_3']);

$str = "T Shirts Vests";
$str[strpos($str, " ")] = '';