obsession

名词 obsession:

1. an irrational motive for performing trivial or repetitive actions against your will
   同义词：compulsion
2. an unhealthy and compulsive preoccupation with something or someone
   同义词：fixation

1. Caused or conditioned by compulsion or obsession.
   强迫的由强迫或压制所引起或制约的
2. Her commitment to a great cause degenerated from a crusade into an obsession.
   她致力於一伟大事业，但其崇高的奋斗精神已变质成为偏执的狂热。

ob.ses.sion

n.（名词）
Compulsive preoccupation with a fixed idea or an unwanted feeling or emotion, often accompanied by symptoms of anxiety.
着魔，萦绕：不由自主地被某一定式的想法或某种不想要的感情困扰，常伴有焦虑的症状
A compulsive, often unreasonable idea or emotion.
妄想：一种不由自主，常常是不合理的想法或情感

【引伸】
obses.sional
adj.（形容词）
obses.sionally
adv.（副词）