Obsession /(?)/

Ob·ses·sion

Obsession

n.
  1. The act of besieging. [archaic]
  2. The state of being besieged; -- used specifically of a person beset by a spirit from without. [archaic]
    Whether by obsession or possession, I will not determine.
    — Burton.
  3. An excessive preoccupation of the thoughts or feelings; the persistent haunting or domination of the mind by a particular desire, idea, or image.
  4. Any driving motive; a compelling goal; -- not necessarily implying a negative judgment, as does sense 3; as, the coach was obsessed with winning the state championship
  5. Something that causes an obsession{3}.
  6. The state of being obsessed.