What is the definition of "obsessive"?

The term "obsessive" is best defined as being overly preoccupied with a particular idea, thought, or activity. When someone is described as obsessive, it indicates that they have excessive attention or fixation that goes beyond regular interest or concern. This characteristic can manifest in various forms, such as compulsive behaviors or persistent thoughts that dominate a person's mental state.

In contrast to the other definitions provided, which do not relate to the notion of intense preoccupation, "obsessive" emphasizes the depth of focus and emotional investment someone may have towards certain subjects or activities. For instance, a person with an obsessive interest in a hobby may spend all their time thinking about it or engaging in related activities, often to the detriment of other aspects of life. This understanding aligns precisely with the notion of being "overly preoccupied," making that the correct choice.