/ Dictionary / Index L letters of administration: Meaning and Definition of Find definitions for: let'ters of administra'tion Pronunciation: [key] — Law. Law. an instrument issued by a court or public official authorizing an administrator to take control of and dispose of the estate of a deceased person. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. letter-size letters of credence Related Content Daily Word Quiz: lunar Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language