Meaning of supergrade

su•per•grade

Pronunciation: (s'pur-grād"), [key]
— n. U.S. Govt.
  1. a high-level rank, Grade 16, 17, or 18, in the federal civil service.
  2. a government employee having such a rank.
—adj.
  1. of, pertaining to, or characteristic of such a rank or employee.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.