Possible Clues:

• Word such as radar, laser
• American buddy introduced Ernie, for one
• 'AWOL' or 'NASA,' e.g.
• Short term for mate in America
• American ringing friend in UNICEF, perhaps
• American ringing friend in NATO, perhaps
• Word made from initial letters of other words
• Ernie is one a friend married
• eg Ernie; radar
• Word like laser or Aids