In Drupal 7, how do I display my taxonomy term fields while creating content when using a checkbox field? I currently have the following below as a taxonomy reference field in one of my content types as a checkbox list widget during content creation. 

Currently its only showing the term name, but I want it to show the term name and its fields. My end results would be something like this:

nc - North Carolina

nj - New Jersey

ny - New York

How can that be done?
I don't think there's a way to do this using the UI, but you should be able to do this using template_preprocess_field().

Store the full version of each acronym as the description on each of your taxonomy terms. The acronym would be the title.

Then you'll want to do something like:

*note that this is all pseudo-code as I don't have a version of Drupal handy to test this, but with some kpr() or var_dump() calls you should be able to debug it for your needs*

&lt;?php
function my_theme_preprocess_field(&amp;$vars) {
  $element = $vars['element'];
  // Modify the output of the taxonomy term field
  if ($element['#field_name'] === 'field_my_taxonomy_term') {
    // Get the title and description
    $item = $vars['items'];
    $acronym = $vars['items'][0]['title'];
    $description = $vars['items'][0]['description'];

    //create the html you want
    $html = '&lt;span&gt;'.$acronym.' - '.$description.'&lt;/span&gt;';

    //now replace the default field markup with your new markup
    $vars['items'][0]['#markup'] = $html;

  }
}
?&gt;