The term 'ADDS ON' can be defined by five different crossword solutions: ANNEXES (7 letters), APPENDS (7 letters), AMENDS (6 letters), AFFIXES (7 letters), and TACKS (5 letters). ANNEXES refers to the act of attaching something to a larger entity, such as a country annexing a territory. APPENDS is similar to ANNEXES, but it is usually used to refer to attaching something to the end of a document or other item. AMENDS is the act of making changes or corrections to something, often to improve it. AFFIXES is the act of attaching something to another object, such as a stamp affixed to an envelope. Finally, TACKS is the act of attaching something with a short nail or pin.