1 (onom.) to rumble (of a stomach)

2 to coo (of a dove)

3 rumbling

4 noisy drinking sound

1 to mutter

2 to feel apprehensive

1 (onom.) for the sound of a bird, an empty stomach etc

1 splash

2 (onom.) for heavy things falling down

1 to hesitate

2 to have second thoughts

3 to be concerned

4 to brood (over sth)

5 to complain