copyTermsToOtherTaxonomy.php

<?php
	/**
	 * This will copy all terms from country taxonomy to area taxonomy
	 * this will also include the child terms, but will not place them in right hierarchy
	 * for this please check the  wp_insert_term() [ https://codex.wordpress.org/Function_Reference/wp_insert_term ] argument in codex and modify the loop
	 * @uses wp_insert_term()
	 * @return boolean
	 */
	function CopyTermsToOtherTaxonomy(){
		static $done;
		$fromTax = 'country';
		$toTax = 'area';
		if(!$done || $done == NULL){
			$args =  array('orderby' => "id", 'hide_empty' => false);
			$countries = get_terms($fromTax, $args); //get_terms( array('country'),$args);
			//var_dump(count($countries)); exit;
			foreach($countries as $country){
				wp_insert_term($country->name, $toTax, array('slug' => $country->slug));
			}
			$done = true;
			return $done;
		}
	}
	add_action('init', 'get_tax_terms');
?>