The "Nick Name" / "Nickname" Field Label is Inconsistent

In the Edit Contact screens, the field is labeled "Nick Name", which is incorrect. When it is displayed for a contact, the label is displayed as "Nickname", which is correct.

If it helps in the debugging process... when adding the field to a Webform in Drupal, it shows up as "Nick Name" in the build screen, which is, again, incorrect. The default label on a Webform is then also incorrect.