Meaning

noun a component that is added to something to improve it

noun the act of adding one thing to another

noun a quantity that is added

originEtymology tree Proto-Indo-European *h₂éd Proto-Italic *ad Proto-Italic *ad- Latin ad- Proto-Indo-European *dʰeh₁- Proto-Indo-European *dʰéh₁tder. Proto-Italic *-ðō Latin -dō Latin addō Latin additiōder. Old French aditionder. Middle English addicioun English addition Sense of “what is added” dates from 14th century, from Middle English addicioun, addition, from Old French adition, from Latin…

Etymology from Wiktionary, CC BY-SA 3.0