add_filter( 'wc_order_statuses', 'wc_renaming_order_status' );
function wc_renaming_order_status( $order_statuses ) {
    foreach ( $order_statuses as $key => $status ) {
        if ( 'wc-completed' === $key ) 
            $order_statuses['wc-completed'] = _x( 'Order Received', 'Order status', 'woocommerce' );
    }
    return $order_statuses;
}