/ ˈrʌmblɪŋ; NAmE / noun
1.
(also used as an adjective) a long deep sound or series of sounds :
the rumblings of thunder
a rumbling noise
( figurative )
the rumblings of discontent
2.
[ usually pl. ] things that people are saying that may not be true
SYN rumour :
There are rumblings that the election may have to be postponed.