The term BY SLIP can be broken down into two crossword solutions: ELAPSE (6 letters) and ERROR (5 letters). ELAPSE is defined as the passing of time, usually in a gradual or subtle way. It is often used to describe the passing of time in a figurative sense, such as when referring to the ELAPSE of a relationship. ERROR, on the other hand, is defined as an act or statement that deviates from what is correct, right, or proper. It is often used to refer to mistakes made in a variety of contexts, such as in a scientific experiment or a business transaction.