addition

noun

1. 1

   the act of adding one thing to another

   the addition of flowers created a pleasing effect

   the addition of a leap day every four years

2. 2

   the arithmetic operation of summing; calculating the sum of two or more numbers

   the summation of four and three gives seven

   four plus three equals seven

3. 3

   a component that is added to something to improve it

   the addition of a bathroom was a major improvement

   the addition of cinnamon improved the flavor

4. 4

   a suburban area laid out in streets and lots for a future residential area

5. 5

   something added to what you already have

   the librarian shelved the new accessions

   he was a new addition to the staff

6. 6

   a quantity that is added

   there was an addition to property taxes this year

   they recorded the cattle's gain in weight over a period of weeks