WordPress - Remove / unregister taxonomies

remove_default_taxonomies.php

<?php 
/**
 * Unregister taxonomies.
 * @param  array $taxonomies Optional. An array of taxonomies. If none are given, defaults to post tags and categories.
 * @return void
 */
function wds_unregister_taxonomies( $taxonomies = array() ) {
	global $wp_taxonomies;

	// Allow an array of taxonomies to be passed. Default to tags and categories if nothing was passed.
	$taxonomies = ( ! empty( $taxonomies ) && is_array( $taxonomies ) ) ? $taxonomies : array( 'post_tag', 'category' );
	foreach ( $taxonomies as $taxonomy ) {
		if ( taxonomy_exists( $taxonomy ) ) {
			unset( $wp_taxonomies[ $taxonomy ] );
		}
	}
}
add_action( 'init', 'wds_unregister_taxonomies' );