/ Dictionary / Index L letters testamentary: Meaning and Definition of Find definitions for: let'ters testamen'tary Pronunciation: [key] — Law. Law. an instrument issued by a court or public official authorizing an executor 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. letters patent letter stock 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