Part of speech: Noun
a component that is added to something to improve it
Example: the addition of a bathroom was a major improvement; the addition of cinnamon improved the flavor
Categories: Component, Constituent, Element
Part of speech: Noun
the act of adding one thing to another
Example: the addition of flowers created a pleasing effect; the addition of a leap day every four years
Categories: Increase, Step-up
Part of speech: Noun
a quantity that is added
Example: there was an addition to property taxes this year; they recorded the cattle's gain in weight over a period of weeks
Categories: Indefinite quantity
Part of speech: Noun
a suburban area laid out in streets and lots for a future residential area
Categories: Suburb, Suburbia, Suburban area
Summation, Plus, Increase, Improver, Gain
The word "addition" comes from Latin additiōnem. It started in Old French adition. Then it appeared in Middle English addicioun.
Each language in this chain added phonetic changes that transformed the original sound.