grumble >> ˈɡrʌmb(ə)l
Definition: [verb] complain about something in a bad-tempered way.
Example: ‘I'm getting old,’ she grumbled
Definition: [verb] make a low rumbling sound.
Example: thunder was grumbling somewhere in the distance
Definition: [verb] (of an internal organ) give intermittent discomfort.
Example: my appendix grumbled for years before it finally got serious
Definition: [noun] a complaint.
Example: the main grumble is that he spends too much time away
Definition: [noun] a low rumbling sound.
Example: in the distance, I heard a grumble of thunder