WordWeb Online

1. Having or showing excessive or compulsive concern with something
   "was absolutely obsessed with the girl"
   - haunted, preoccupied, taken up
    
2. Influenced or controlled by a powerful force such as a strong emotion
   - possessed

1. Haunt like a ghost; pursue
   - haunt, ghost
    
2. Be preoccupied with something
   "She is obsessing over her weight"

See also: concerned, controlled, obsession, obsessive

Type of: preoccupy, worry

Encyclopedia: Obsess