sum
sum /ˈsʌm/
noun

()
A quantity of money
(
amount of money
, sum of money
, sum
, amount
)
a quantity of money
He borrowed a large sum
he borrowed a large sum
The amount he had in cash was insufficient
the amount he had in cash was insufficient

()
A quantity obtained by the addition of a group of numbers
(
sum
, amount
, total
)
a quantity obtained by the addition of a group of numbers

()
The whole amount
(
totality
, aggregate
, sum
, total
)
the whole amount
The cashier calculated the total amount of the purchase.
The cashier calculated the total amount of the purchase.

()
The choicest or most essential or most vital part of some idea or experience
(
centre
[Canadian, British] , gist
, heart and soul
, inwardness
, core
, kernel
, marrow
, meat
, nittygritty
, nub
, pith
, sum
, center
[American] , essence
, heart
, substance
)
the choicest or most essential or most vital part of some idea or experience
The gist of the prosecutor's argument
the gist of the prosecutor's argument
The heart and soul of the Republican Party
the heart and soul of the Republican Party
The nub of the story
the nub of the story

()
The final aggregate
(
sum total
, summation
, sum
)
the final aggregate
The sum of all our troubles did not equal the misery they suffered
the sum of all our troubles did not equal the misery they suffered

A set containing all and only the members of two or more given sets
(
join
, sum
, union
)
a set containing all and only the members of two or more given sets
Let C be the union of the sets A and B
let C be the union of the sets A and B
verb

Determine the sum of
(
add together
, sum
, sum up
, tally
, add
, add up
, summate
, tot
, tot up
, total
, tote up
)
determine the sum of
Add all the people in this town to those of the neighboring town
Add all the people in this town to those of the neighboring town

Be a summary of
(
sum
, sum up
, summarise
[British] , summarize
)
be a summary of
The abstract summarizes the main ideas in the paper
The abstract summarizes the main ideas in the paper