Remove an item from the Admin menu

wp_remove_menu.php

<?php

/**
 * remove_menu
 *
 * Remove an item from the Admin menu
 * If top-level menu item, pass the slug as a string
 * If submenu item, pass an array of parent and submenu slugs
 *
 * @param string|array $item Slug or parent slug & slug to be removed
 */
function remove_menu( $item ) {
	add_action( 'admin_menu', function() use ( $item ) {
		if ( is_string( $item ) ) {
			remove_menu_page( $item );
		} else {
			remove_submenu_page( $item[0], htmlentities( $item[1] ) );
		}
	} );
}