Encara no tenim significats per a "grumble unintelligibly".
1He grumbled unintelligibly or failed to answer at all.
2Wharton grumbled unintelligibly, but it was plain that he was not entirely displeased at his son's prank.
3Choosing a low, bushy pinyon tree as best suited to the purposes of a lazy climber, Stacy climbed it, grunting and grumbling unintelligibly.