Dictionary.com
definitions
  • synonyms

obsess

[uhb-ses]
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.
Show More
verb (used without object)
  1. to think about something unceasingly or persistently; dwell obsessively upon something.
Show More

Origin of obsess

1495–1505; < Latin obsessus, past participle of obsidēre to occupy, frequent, besiege, equivalent to ob- ob- + -sid(ēre) combining form of sedēre to sit1
Related formsob·sess·ing·ly, adverbob·ses·sor, noun
Can be confusedabscess obsess

Synonyms for obsess

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for obsessor

obsess

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
Show More

Word Origin for obsess

C16: from Latin obsessus besieged, past participle of obsidēre, from ob- in front of + sedēre to sit
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for obsessor

obsess

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.

Show More
Online Etymology Dictionary, © 2010 Douglas Harper