sum

nouns

a quantity of money
"he borrowed a large sum"; "the amount he had in cash was insufficient"
a quantity obtained by the addition of a group of numbers
is derived from
the final aggregate
"the sum of all our troubles did not equal the misery they suffered"
is derived from
is derived from
the choicest or most essential or most vital part of some idea or experience
"the gist of the prosecutor's argument"; "the heart and soul of the Republican Party"; "the nub of the story"
is derived from
the whole amount
is derived from
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"

verbs

be a summary of
"The abstract summarizes the main ideas in the paper"
is derived from
determine the sum of
"Add all the people in this town to those of the neighboring town"
is derived from