Preoccupy completely is a term used to describe a state of being overly focused on something. It is often used to describe a person who is so preoccupied with a certain task or idea that they are unable to focus on anything else. The term can also be used to describe a situation in which someone is so focused on one thing that they are unable to take into account other factors. The crossword solution for this term is 'OBSESS, ' which means to think about something constantly and to be excessively concerned with it.