WordPress at a glance
action is not described

woocommerce_update_customer action-hook . WC 1.0

Usage

add_action( 'woocommerce_update_customer', 'action_function_name_7751', 10, 2 );
function action_function_name_7751( $customer_id, $customer ){
	// action...
}
$customer_id
-
$customer
-

Where the hook is called

WC_Customer_Data_Store::update()
woocommerce_update_customer
woocommerce/includes/data-stores/class-wc-customer-data-store.php 214
do_action( 'woocommerce_update_customer', $customer->get_id(), $customer );

Where in WP core the hook is used WooCommerce

woocommerce/packages/woocommerce-admin/src/Schedulers/CustomersScheduler.php 30
add_action( 'woocommerce_update_customer', array( __CLASS__, 'schedule_import' ) );