grumblingly

/ˈɡrʌmblɪŋli/
adverb
  1. In a manner that shows dissatisfaction or complaint, often with a low muttering voice.
    • He grumblingly agreed to help with the dishes.
    • She grumblingly handed over her phone when the teacher asked.
    • The dog grumblingly moved off the couch when told.
Antonyms