obsessionist Definition

obsession
noun

1. A persistent or dominating thought, idea, feeling, etc.

Thesaurus: complex, fixation, infatuation, mania, preoccupation, passion, fetish, fascination, compulsion, hang-up (slang).
2. psychol.
A form of neurosis in which a recurring thought, feeling or impulse, generally of an unpleasant nature and with no rational basis, preoccupies a person against their will and is a source of constant anxiety.
3. The act of obsessing or state of being obsessed.

Derivative: obsessional
adj

Derivative: obsessionally
adverb

Derivative: obsessionist
noun

Etymology: Early 20c in sense 2; 16c.