Someone or something that is motionless is not moving at all.
例句
He has this ability of being able to remain as motionless as a statue, for hours on end...他有本事连续几个小时一动不动，像雕塑一样。Her hands were motionless...她双手静止不动。
英汉词典释义
adj.
不动的,静止的
A silent movie doesn’t mean it is motionless.无声电影并非没有动作。I urged him to rest,but he remained motionless.我叫他休息,可他仍然不动。She sat motionless,waiting for their decision.她坐在那里一动不动,等候他们作出决定。