Grumbled, past participle of grumble. Synonyms in the same form.
Mutter
muttered, complained, rumbled, moaned, groaned, growled, croaked, snarled, roared, gnarled, murmured
Grouch
grouched, scolded, bitched, bellyached, griped, groused
Other
yammered, pinched
All synonyms for grumble →