Obsess

• POS: Verb (transitive)
• HYPHEN: ob=sess

CIDE DICTIONARY

Obsess, v. t. [L. obsessus, p. p. of obsidere to besiege; ob (see Ob-) + sedere to sit.].

•  To besiege; to beset.  Sir T. Elyot.  [1913 Webster]
•  To excessively preoccupy the thoughts or feelings of; to haunt the mind persistently.  [PJC]

Obsess, v. i. 

 To be excessively or persistently preoccupied with something; -- usually used with on or over; as, to obsess over an imagined insult.  [PJC]
"At all ages children are driven to figure out what it takes to succeed among their peers and to give these strategies precedence over anything their parents foist on them. Weary parents know they are no match for a child's peers, and rightly obsess over the best neighborhood in which to bring their children up."  [PJC]

OXFORD DICTIONARY

Obsess, v.tr. (often in passive) preoccupy, haunt; fill the mind of (a person) continually.

Derivative

obsessive adj. & n. obsessively adv. obsessiveness n.

Etymology

L obsidere obsess- (as OB-, sedere sit)

THESAURUS

Obsess

absorb, absorb the attention, arrest, be remembered, bedevil, beset, bewitch, burden, catch, charm, compel, control, crush one, demonize, devilize, diabolize, dominate, drive, enchant, engage, engage the attention, engage the mind, engage the thoughts, engross, engross the mind, engross the thoughts, enthrall, exercise, exhaust, fascinate, grab, grip, hant, harass, haunt, haunt the memory, hex, hold, hold spellbound, hold the interest, hoodoo, hypnotize, immerse, impel, infatuate, involve, involve the interest, jinx, make an impression, mesmerize, monopolize, never be forgotten, not let go, occupy, occupy the attention, oppress, overlook, penetrate, plague, possess, preoccupy, prey on, rankle, sink in, spellbind, spook, take over, take up, tire, torment, voodoo, wear out, wear upon one, weary, weigh upon, weight down, witch