All add-on synonyms

noun add-on

• supplement — something added to complete a thing, supply a deficiency, or reinforce or extend a whole.
• preservative — something that preserves or tends to preserve.
• addition — An addition to something is a thing which is added to it.
• accompaniment — The accompaniment to a song or tune is the music that is played at the same time as it and forms a background to it.
• flavor enhancer — a substance added to food in order to enhance or intensify its flavor: Salt is a common flavor enhancer.