/ Dictionary / Index A arithmetic mean: Meaning and Definition of Find definitions for: ar'ithmet'ic mean' Pronunciation: [key] — Statistics. Statistics. the mean obtained by adding several quantities together and dividing the sum by the number of quantities:Also called the arithmetic mean of 1, 5, 2, and 8 is 4. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. arithmetic/logic unit arithmetic progression Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language