Bombinating is a seldom-used word that means to make a buzzing or humming noise. There are several antonyms for this word that refer to more peaceful and quiet sounds. The opposite of bombinating could be a whisper, a hush, a murmur, or a lullaby. All of these words have connotations of soothing, calming, or gentle sounds, and they are a world away from the intense and noisy activity implied by bombinating. So if you need to describe a tranquil and serene atmosphere, you might use one of these antonyms for bombinating to create a calming effect in your writing.