[ suhm ]
See synonyms for sum on
  1. the aggregate of two or more numbers, magnitudes, quantities, or particulars as determined by or as if by the mathematical process of addition: The sum of 6 and 8 is 14.

  2. a particular aggregate or total, especially with reference to money: The expenses came to an enormous sum.

  1. an indefinite amount or quantity, especially of money: to lend small sums.

  2. a series of numbers or quantities to be added up.

  3. an arithmetical problem to be solved, or such a problem worked out and having the various steps shown.

  4. the full amount, or the whole.

  5. the substance or gist of a matter, comprehensively or broadly viewed or expressed: the sum of his opinions.

  6. concise or brief form: in sum.

  7. Mathematics.

    • the limit of the sequence of partial sums of a given infinite series.

  8. a summary.

verb (used with object),summed, sum·ming.
  1. to combine into an aggregate or total (often followed by up).

  2. to ascertain the sum of, as by addition.

  1. to bring into or contain in a small compass (often followed by up).

verb (used without object),summed, sum·ming.
  1. to amount (usually followed by to or into): Their expenses summed into the thousands.

Verb Phrases
  1. sum up,

    • to reckon: We summed up our assets and liabilities.

    • to bring into or contain in a brief and comprehensive statement; summarize: to sum up the case for the prosecution.

    • to form a quick estimate of: I summed him up in a minute.

Origin of sum

First recorded in 1250–1300; (noun) Middle English summe, from Latin summa “sum,” noun use of feminine of summus “highest,” superlative of superus (see superior); (verb) Middle English summen (from Old French summer), from Medieval Latin summāre, derivative of summa

synonym study For sum

1. See number.

Other words from sum

  • sumless, adjective
  • sum·less·ness, noun
  • outsum, verb (used with object), out·summed, out·sum·ming.

Words that may be confused with sum

Other definitions for SUM (2 of 3)


  1. surface-to-underwater missile.

Other definitions for sum- (3 of 3)


  1. variant of sub- before m: summon. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use sum in a sentence

  • There is little difficulty in summing up their tenets: it is "Reverence, without servility."

  • "The conditions all along the line are almost revolutionary," was Ripley's summing-up of the situation.

    The Wreckers | Francis Lynde
  • Summing up what we have discovered about the nature of Essence, we find first three genera.

    Plotinos: Complete Works, v. 3 | Plotinos (Plotinus)
  • It had been agreed that Sandoval, who possessed the most oratorical ability, should deliver the last toast as a summing up.

    The Reign of Greed | Jose Rizal
  • Summing up our experiences, we agreed that we enjoyed the life thoroughly, but much preferred marching to sitting still.

    In the Ranks of the C.I.V. | Erskine Childers

British Dictionary definitions for sum (1 of 2)


/ (sʌm) /

    • the result of the addition of numbers, quantities, objects, etc

    • the cardinality of the union of disjoint sets whose cardinalities are the given numbers

  1. one or more columns or rows of numbers to be added, subtracted, multiplied, or divided

  1. maths the limit of a series of sums of the first n terms of a converging infinite series as n tends to infinity

  2. (plural) another name for number work

  3. a quantity, esp of money: he borrows enormous sums

  4. the essence or gist of a matter (esp in the phrases in sum, in sum and substance)

  5. a less common word for summary

  6. archaic the summit or maximum

  7. (modifier) complete or final (esp in the phrase sum total)

verbsums, summing or summed
  1. (often foll by up) to add or form a total of (something)

  2. (tr) to calculate the sum of (the terms in a sequence)

Origin of sum

C13 summe, from Old French, from Latin summa the top, sum, from summus highest, from superus in a higher position; see super

British Dictionary definitions for sum (2 of 2)


/ (sʊm) /

nounplural sumy (sʊmɪ)
  1. the standard monetary unit of Uzbekistan, divided into 100 tiyin

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for sum


[ sŭm ]

  1. The result of adding numbers or quantities. The sum of 6 and 9, for example, is 15, and the sum of 4x and 5x is 9x.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.