Definition of "Sum" :

noun: the whole amount

noun: a quantity obtained by the addition of a group of numbers

noun: the choicest or most essential or most vital part of some idea or experience

noun: the final aggregate

"The sum of all our troubles did not equal the misery they suffered."

noun: a set containing all and only the members of two or more given sets

noun: a quantity of money

"He borrowed a large sum."

verb: determine the sum of

verb: be a summary of

"The abstract summarizes the main ideas in the paper."