This will change the title (Description) of the description tab to something else - here 'Event information'. Use a suitable txt_domain for translations.

change_product_description_tab_title.php

<?php 
/* This will change the title (Description) of the description tab to something else 
 * @origin https://wp-pro.dk/guides/tilpas-woocommerce-faneblades-titel-og-overskrift
 */

add_filter( 'woocommerce_product_tabs', 'eid_change_product_description_tab_title', 10, 1 );
function eid_change_product_description_tab_title( $tabs ) {
  global $post;
	if ( isset( $tabs['description']['title'] ) )
		$tabs['description']['title'] = __('Event information', 'txt_domain');  // change for something else, ready for translation 
	return $tabs;
}