If you are preoccupied, you are thinking a lot about something or someone, and so you hardly notice other things. Tom Banbury was preoccupied with the missing Shepherd child and did not want to devote time to the new murder. thinking about something a lot, with the result that you do not pay attention to other things
deeply absorbed in thought; "as distant and bemused as a professor listening to the prattling of his freshman class"; "lost in thought"; "a preoccupied frown"
{s} busy, engaged; lost in thought, occupied with meditations; taken, previously occupied, previously acquired (property)
having or showing excessive or compulsive concern with something; "became more and more haunted by the stupid riddle"; "was absolutely obsessed with the girl"; "got no help from his wife who was preoccupied with the children"; "he was taken up in worry for the old woman"