Field inheritance (Drupal 7)
Strictly speaking, fields can't "inherit", no, but you can almost do it anyway.

Drupal 7 comes with a generic "File" field, and a more specific "Image" field. Technically, one could say that Image inherits from File, but the way it's done is simply that for a lot of it's hook implementations, it just calls back to file.

Example code:

/**
 * Implements hook_field_load().
 */
function image_field_load($entity_type, $entities, $field, $instances, $langcode, &amp;$items, $age) {
  file_field_load($entity_type, $entities, $field, $instances, $langcode, $items, $age);
}


As far as I know, this is as close as you can get.