/ Dictionary / Index U upper arm: Meaning and Definition of Find definitions for: up'per arm' Pronunciation: [key] the part of the arm between the shoulder and the elbow. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Upper Arlington upper atmosphere Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language