The tab labels on the single product view are 'Description', 'Additional Information' and 'Reviews' by default. You can rename the 'Reviews' tab with this code.
/**
* Rename reviews tab label on single product
*/
// Renames the reviews tab label on the single product page to an alternative text.
add_filter( 'woocommerce_product_reviews_tab_title', 'sc_woo_rename_reviews_product_tab_label' );
function sc_woo_rename_reviews_product_tab_label() {
return 'Feedback';
}