Delete ALL Terms In A Taxonomy (Use With Caution)

wordpress-bulk-taxonomy-terms-delete.php

<?php

global $wpdb;
$taxonomy_slug = 'area';

$wpdb->query( "DELETE a, b, c, d
					FROM {$wpdb->term_taxonomy} a
					LEFT JOIN {$wpdb->terms} b
						ON (a.term_id = b.term_id)
					LEFT JOIN {$wpdb->term_relationships} c
						ON (a.term_taxonomy_id = c.term_taxonomy_id)
					LEFT JOIN {$wpdb->termmeta} d
						ON (a.term_id = d.term_id)
					WHERE a.taxonomy = {$taxonomy_slug}" );