The term 'Pick Up the Tab' is an idiom that means to PAY for something, usually a meal or outing. The crossword solutions TREAT (5 letters), PAY (3 letters), and FOOTTHEBILL (11 letters) all refer to this idiom. TREAT implies that someone is being generous and paying for something for someone else, PAY is a verb meaning to give money in exchange for goods or services, and FOOTTHEBILL is a phrase meaning to PAY the entire bill. All three of these solutions are related to the idiom 'Pick Up the Tab, ' which means to PAY for something.