till
If you've ever worked in retail sales or in some other customer service capacity where you have to handle money (e.g. ring up transactions) such as a convenience store cashier, bartender, grocery store clerk, etc., then you'll know that a till is just another name for a cash register.
Example:
Hey Jason, please don't forget to put that $20 bill into the till; you remember what happened the last time that you "forgot"!
Hey Jason, please don't forget to put that $20 bill into the till; you remember what happened the last time that you "forgot"!