The term 'acted upon' can be broken down into four crossword solutions: OPERAND (7 letters), STAGE (5 letters), AFFECTED (8 letters), and ATE (3 letters). An operand is an object or value on which a mathematical or logical operation is performed. A STAGE is a period of time in a process of change or development. To be AFFECTED is to be influenced by something, usually in a negative way. Lastly, to eat is to take in food through the mouth. Therefore, the term 'acted upon' can be interpreted as being influenced by something, usually in a negative way, over a period of time, with the result of taking in something.