Drupal views show all taxonomy of specified vocabulary
All you gotta do is create a view of Taxonomy Terms and use fields 



Then use a template file for your view.

In your template file all you gotta do is load your node's taxonomy term field value and compare it the view's taxonomy term name. If it's equal we print the underline &lt;u&gt;. 

&lt;?php

    $node = node_load(arg(1));
    $node_term = check_plain($node-&gt;field_name[0]['value']);

    if ($fields["name"]-&gt;content == $node_term) { 
        print '&lt;u&gt;' . $fields["name"]-&gt;raw == $node_term . '&lt;/u&gt;'; 
      } else { 
        print $fields["name"]-&gt;content; 
      }

?&gt;