|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|1.||psychiatry a persistent idea or impulse that continually forces its way into consciousness, often associated with anxiety and mental illness|
|2.||a persistent preoccupation, idea, or feeling|
|3.||the act of obsessing or the state of being obsessed|
obsession ob·ses·sion (əb-sěsh'ən, ŏb-)
Compulsive preoccupation with an idea or an unwanted feeling or emotion, often accompanied by symptoms of anxiety.
A compulsive, often unreasonable idea or emotion.