- 心神不定 [xīn shén bú dìng]
- be anxious and preoccupied; agitated; be on tenterhooks; be distracted; be all in a twitter; feel ill at ease; feel restless; fidgety; have no peace of mind; in a state of discomposure; out of sorts; miles away; wandering in thought:
I don't know what is on his mind; he always looks restless. 不知他有什么事，老是心神不定的样子。
When they didn't get back by midnight, I got that sinking feeling.