obsessed

adjective

1. having an obsession (usually followed by with or by): He is obsessed with eliminating guilt.
2. having or displaying signs of an obsession: The audiophile entered the record store wearing an obsessed smile.

verb (used with object)

1. to dominate or preoccupy the thoughts, feelings, or desires of (a person); beset, trouble, or haunt persistently or abnormally: Suspicion obsessed him.

verb (used without object)

2. to think about something unceasingly or persistently; dwell obsessively upon something.

verb

1. (tr; when passive, foll by with or by) to preoccupy completely; haunt
2. (intr; usually foll by on or over) to worry neurotically or obsessively; brood

adj.mid-15c., “tormented, obsessed,” past participle adjective from obsess. Originally especially “possessed” by a devil, etc. v.c.1500, “to besiege,” from Latin obsessus, past participle of obsidere “watch closely; besiege, occupy; stay, remain, abide” literally “sit opposite to,” from ob “against” (see ob-) + sedere “sit” (see sedentary). Of evil spirits, “to haunt,” from 1530s. Psychological sense is 20c. Related: Obsessed; obsessing.