/ Dictionary / Index U under secretary: Meaning and Definition of Find definitions for: un'der sec'retary Pronunciation: [key] — (often caps.) an official who is subordinate to a principal secretary, as in the U.S. cabinet: Under Secretary of the Treasury. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: undersecretary (Thesaurus) undersecretariat undersell Related Content Daily Word Quiz: fidelity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language