The term 'substitute for money' can be summed up by the crossword solution of 'tokens' (6 letters). Tokens are a form of currency that can be used in place of money. They are typically used in situations where cash is not accepted, such as in arcades or amusement parks. Tokens are also used to reward customers for loyalty or to incentivize certain behaviors. Tokens are usually made of metal or plastic and have a predetermined value.