obsess

Obsess is a verb meaning to dominate or preoccupy the mind of someone or something, often persistently and in a way that is hard to dismiss. It describes a fixation on a person, idea, object, or activity and is typically used with with, over, or about: be obsessed with something; obsess over something. In modern usage, the regular phrasal forms be obsessed with and obsess over are standard; using obsess without a prepositional phrase is rare and can sound archaic or informal.

Etymology and related forms: The verb derives from the Latin obsessus, the past participle of obsidere, meaning to besiege or blockade. It entered English in the late 16th century, with influence from French and Latin. The related noun is obsession, the adjective obsessive, and the adverb obsessively.

Usage and nuance: Obsess carries a strong, often negative or intense connotation, implying preoccupation that may be excessive or irrational. In clinical contexts, obsessions refer to intrusive thoughts associated with obsessive-compulsive disorder (OCD); however, everyday language uses obsess to describe broad preoccupations rather than medical conditions. The adjective obsessive and the noun obsession convey similar intensities, with obsessive used to describe a person or behavior and obsession to name the preoccupation itself.

Examples are common in media and everyday speech: someone can be obsessed with a celebrity, a hobby, or a plan, reflecting a high degree of focus that can color judgments and behavior.