inertia
/ɪˈnɜ:ʃə; ɪn`əʃə/ n[U]
1 (usu derog 通常作贬义)
(a) lack of vigour; lethargy 无活力; 迟钝
I'm unable to throw off this feeling of inertia. 我无法摆脱这种懒散的感觉.
(b) tendency to remain unchanged 惰性; 保守
Because of the sheer inertia of the system many badly needed reforms were never introduced. 纯粹是由於制度本身有惰性, 很多事急需改革却从未实行.
2 (physics 物) property of matter by which it remains in a state of rest or, if in motion, continues moving in a straight line, unless acted upon by an external force 惯性.