1. Make an addition
   "Let's add on to this" 
2. Add to the very end
   - append, supplement, affix

1. A component that is added to something to improve it
   - addition, improver 
2. A supplementary component that improves capability
   - accessory, appurtenance, supplement

Derived forms: adding on, adds on, add-ons, added on

Type of: add, attach, component, constituent, element

Encyclopedia: Add-on

• milk leg
• milk of magnesia
• milk powder
• milk pox
• milk pudding
• milk punch
• Milk River
• milk run
• milk sickness
• milk snake
• milk sugar
• milk thistle
• milk tooth
• milk whey
• milk-sick
• milk-vetch
• milk-white
• milkcap
• milker
• milkily
• milkiness
• milking machine
• milking shorthorn
• milking stool
• milkless