WordWeb Online

1. Deeply absorbed in thought
   "a preoccupied frown";
   - bemused, deep in thought, lost
    
2. Having or showing excessive or compulsive concern with something
   "he got no help from his wife, who was preoccupied with the children";
   - haunted, obsessed, taken up

1. Engage or engross the interest or attention of beforehand or occupy urgently or obsessively
   "His work preoccupies him"; "The matter preoccupies her completely--she cannot think of anything else"
    
2. Occupy or take possession of beforehand or before another or appropriate for use in advance
   "the army preoccupied the hills"

See also: concerned, thoughtful

Type of: arrogate, assume, command, control, seize, take over, usurp