The English term "growl, mutter, grumble" matches the Dutch term "morren"

other english words that include "growl" : dutch :
growl, grumble kankeren
growl, grumble mopperen
growl, grumble sputteren
other english words that include "mutter" : dutch :
mutter, buzz, hum brommen
mutter mompelen
mutter mummelen