Origin of sum

1250–1300; (noun) Middle English summe < Latin summa sum, noun use of feminine of summus highest, superlative of superus (see superior); (v.) Middle English summen (< Old French summer) < Medieval Latin summāre, derivative of summa
Related formssum·less, adjectivesum·less·ness, nounout·sum, verb (used with object), out·summed, out·sum·ming.
Can be confusedsome sum (see usage note at some)

Definition for sum (2 of 4)

SUM


surface-to-underwater missile.

Definition for sum (3 of 4)

sum-


variant of sub- before m: summon.

Definition for sum (4 of 4)

cogito, ergo sum

[ koh-gi-toh er-goh soo m; English koj-i-toh ur-goh suhm, er-goh ]
/ ˈkoʊ gɪˌtoʊ ˈɛr goʊ ˈsʊm; English ˈkɒdʒ ɪˌtoʊ ˈɜr goʊ ˈsʌm, ˈɛr goʊ /

Latin.

I think, therefore I am (stated by Descartes as the first principle in resolving universal doubt).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for sum

British Dictionary definitions for sum (1 of 3)

sum

1
/ (sʌm) /

noun

verb sums, summing or summed

(often foll by up) to add or form a total of (something)
(tr) to calculate the sum of (the terms in a sequence)
See also sum up

Word Origin for 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 3)

sum

2
/ (sʊm) /

noun plural sumy (sʊmɪ)

the standard monetary unit of Uzbekistan, divided into 100 tiyin

British Dictionary definitions for sum (3 of 3)

cogito, ergo sum

/ Latin (ˈkɒɡɪˌtəʊ ˈɜːɡəʊ ˈsʊm) /

I think, therefore I am; the basis of Descartes' philosophy
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

Word Origin and History for sum

sum


n.

late 13c., "quantity or amount of money," from Anglo-French and Old French summe (13c.), from Latin summa "total number, whole, essence, gist," noun use of fem. of summus "highest," from PIE *sup-mos-, from root *uper "over" (see super-).

The sense development from "highest" to "total number" is probably via the Roman custom of adding up a stack of figures from the bottom and writing the sum at the top, rather than at the bottom as we do now (cf. the bottom line). Meaning "total number of anything" is recorded from late 14c. Meaning "essence of a writing or speech" also is attested from late 14c. The verb is attested from c.1300; meaning "briefly state the substance of" (now usually with up) is first recorded 1620s. Sum-total is attested from late 14c., from Medieval Latin summa totalis.

Online Etymology Dictionary, © 2010 Douglas Harper

Science definitions for sum

sum

[ sŭm ]

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.