rumbling          
noun uk/ˈrʌm.bəl.ɪŋ/ /ˈrʌm.blɪŋ/ us/ˈrʌm.bəl.ɪŋ/ /ˈrʌm.blɪŋ/
 [ C usually plural ]不满情绪;不满的迹象 
a sign of anger or disagreement
  There are rumblings of annoyance throughout the workforce. 员工们普遍流露出怨愤情绪。 
  [ C usually singular ]发出隆隆声;发出辘辘声;发出低沉连续的响声 
a continuous low sound
  the rumbling of distant guns/thunder 远处隆隆的炮声/雷声