niggle
noun /ˈnɪɡl/
  /ˈnɪɡl/
- (British English) a small criticism or complaint轻微的批评;小牢骚 - My only niggle is that they should have told me sooner.我唯一的不满是他们应该早点告诉我。 
-  niggle about/over something niggles over ticket prices关于票价的争论 
 
- My only niggle is that they should have told me sooner.
- a slight feeling, such as worry, doubt, etc. that does not go away一丝挥不去的烦恼(或疑虑等) - a niggle of doubt一丝挥之不去的疑虑 
- In his mind there was that same old niggle—had he done the right thing?在他的脑海里,还是那个老黑鬼——他做得对吗? 
 
- a niggle of doubt
- a slight pain轻微疼痛 - He gets the occasional niggle in his right shoulder.他的右肩有时隐隐作痛。 
 
- He gets the occasional niggle in his right shoulder.
词源early 17th cent. (in the sense ‘do in an ineffectual way’): apparently of Scandinavian origin; compare with Norwegian nigla. Current senses date from the late 18th cent.