loop-through-tax-wp-query.php

 <?php $custom_terms = get_terms('mytaxonomyname');
 
            foreach($custom_terms as $custom_term) {
                wp_reset_query();
                $args = array('post_type' => 'myposttypename',
                    'mytaxonomyname' => 'taxonomyitem', // might be unneccessary - test this
                    'tax_query' => array(
                        array(
                            'taxonomy' => 'mytaxonomyname',
                            'field' => 'slug',
                            'terms' => $custom_term->slug,
                            'operator' => 'AND',
                        ),
                    ),
                 );

                 $loop = new WP_Query($args);
                 if($loop->have_posts()) {
                    echo '<h2>'.$custom_term->name.'</h2>';
                    echo '<dl class="vertical tabs">';
                    while($loop->have_posts()) : $loop->the_post();
                        echo '<dd><a href="'.get_permalink().'" title="' . get_the_title() .'">'.get_the_title().'</a></dd>';
                    endwhile;
                    echo '</dl>';
                 } 
            } ?>