addition

addition (http://definr.com/addition)

     n 1: a component that is added to something to improve it; "the
          addition of a bathroom was a major improvement"; "the
          addition of cinammon improved the flavor" [syn: improver]
     2: 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" [ant: subtraction]
     3: something added to what you have already; "the librarian
        shelved the new accessions"; "he was a new addition to the
        staff" [syn: accession]
     4: 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" [syn: increase, gain]
     5: a suburban area laid out in streets and lots for a future
        residential area
     6: 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" [syn: summation,
         plus]