Other forms: obsessions
An obsession is a thought that will not leave you alone. An obsession with detail, become an obsession, his lifelong obsession.
In casual speech it is a strong enthusiasm — an obsession with old maps — and carries no criticism. In psychiatry it is precise: obsessions are unwanted intrusive thoughts, and obsessive-compulsive disorder involves them alongside compulsions performed to relieve the anxiety. The two uses are far apart and the casual one has made the clinical one harder to explain. Note obsessed, obsessive, and obsess over, which is the usual verb.
1nounobsessionA thought that will not leave you alone.
“His obsession with cleanliness means he washes his hands every few minutes.”
obsession is a persistent thought.
Latin obsessio means a besieging, from obsidere — to sit down before a city. An obsession is a siege of the mind, and the metaphor is exact: something outside settles in and will not go away.
Latin
obsessio — a besieging
English, today
obsession
Built from
From Latin obsessio (“a besieging”), from obsidere (“to besiege”); see obsess. Equivalent to obsess + ion.
Etymology from Wiktionary, CC BY-SA