<?php
$terms = get_terms( 'custom_taxonomy_slug' );
if ( ! empty( $terms ) && ! is_wp_error( $terms ) ){
foreach ( $terms as $term ) { ?>


<?php echo $term->name ?>
 <ul class="prod-list">
<?php
$args = array( 'posts_per_page' => -1, 'offset'=> 0, post_type => 'custom_post_slug', 'tax_query' => array(
array(
'taxonomy' => 'custom_taxonomy_slug',
'field' => 'slug',
'terms' => $term->slug,
),
),
);
$myposts = get_posts( $args );
foreach ( $myposts as $post ) : setup_postdata( $post ); ?>

<li><a href="<?php the_permalink() ?>"><?php the_title(); ?></a></li>


<?php
endforeach;
wp_reset_postdata();?>
</ul>

<?php }
} ?>