OBSESS (ON) is a term that describes an intense focus on something or someone. It is often used to describe an unhealthy preoccupation with a certain idea or person. The two crossword solutions for this term are FIXATE (6 letters) and DWELL (5 letters). FIXATE means to concentrate intently on something, while DWELL means to think or talk about something for a long period of time. Both words can be used to describe the same concept of OBSESS (ON).