1. preoccupy or fill the mind of (someone) continually, intrusively, and to a troubling extent: "he was obsessed with the theme of death"
▪ (of a person) be preoccupied with or constantly worrying about something:"her husband, who is obsessing about the wrong she has done him"
Word Originlate Middle English (in the sense ‘haunt, possess’, referring to an evil spirit): from Latin obsess- ‘besieged’, from the verb obsidere, from ob- ‘opposite’ + sedere ‘sit’. The current sense dates from the late 19th century.
