Quid pro quo is a Latin phrase meaning 'something for something' and is used to describe a situation in which two parties exchange goods or services of equal value. The term is often used in business transactions, where one party provides something of value in exchange for something else of equal value from the other party. In the crossword, the solutions EQUIVALENT (10 letters), SWAP (4 letters), TRADE (5 letters), TRADEOFF (8 letters), and TITFORTAT (9 letters) all refer to this concept of exchanging goods or services of equal value.