Meaning of ambassador-at-large

am•bas•sa•dor-at-large

Pronunciation: (am-bas'u-dur-ut-lärj', -dôr"), [key]
— pl. am•bas•sa•dors-at-large.
  1. an ambassador who is not assigned to a particular diplomatic post but is appointed on a special mission.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.