AWOL
 /ˈeıˌwɑːl/  adj  
  : absent from the armed forces without permission
   Three soldiers were AWOL.
   The soldiers went AWOL at the first chance.
  broadly : absent or missing
   The Senator has been AWOL for the last three votes.
   My keys have gone AWOL. I can't find them anywhere.
  ◇ AWOL comes from a phrase used in the military: absent without leave.
  AWOL  noun  ,  pl   AWOLs [  count  ]
   Four AWOLs [=four soldiers who have gone AWOL] are still missing from their unit.