Definition of sum
1
: an indefinite or specified amount of money
2
: the whole amount : aggregate
3
: the utmost degree : summit
- reached the sum of human happiness
4 a
: a summary of the chief points or thoughts : summation
- the sum of this criticism follows
- —C. W. Hendel
b
: gist
- the sum and substance of an argument
5 a (1)
: the result of adding numbers
- the sum of 5 and 7 is 12
(2)
: the limit of the sum of the first n terms of an infinite series as n increases indefinitely
b
: numbers to be added;
broadly
: a problem in arithmetic
c (1)
: disjunction 2
(2)
: union 2d
