Drupal: Programmatically remove a term from multiple nodes

taxonomy_term_remove_from_nodes.php

// ID of taxonomy term to remove.
$tid = 5;

// Name of the taxonomy field where the term is found.
$field_name = 'field_NAME';

_taxonomy_term_remove_from_nodes($tid, $field_name);

function _taxonomy_term_remove_from_nodes($tid, $field_name) {
  $nids = taxonomy_select_nodes($tid, FALSE, FALSE);
  $nodes = node_load_multiple($nids);
  
  if (empty($nodes)) return;
  
  foreach ($nodes as $node) {
    $field = &$node->$field_name[LANGUAGE_NONE];
    foreach ($field as $key => $term) {
      if ($term['tid'] == $tid) {
        unset($field[$key]);
        node_save($node);
      }
    }
  }
}