grunt

Noun

• medium-sized tropical marine food fishes that utter grunting sounds when caught

• an unskilled or low-ranking soldier or other worker
  • infantrymen in Vietnam were called grunts
    
  • he went from grunt to chairman in six years
    

• the short low gruff noise of the kind made by hogs

Verb

• issue a grunting, low, animal-like noise
  • He grunted his reluctant approval