The word "galumphing" means moving in a clumsy or noisy manner, and there are several antonyms that can be used to describe the opposite of this behavior. These include graceful, elegant, nimble, agile, sprightly, and light-footed. Each of these words evokes a sense of smoothness and fluidity in movement, as opposed to the haphazard and clunky nature of galumphing. Other antonyms for galumphing might include quiet, gentle, and calm, as these words suggest a more subdued approach to movement. Ultimately, the choice of antonym will depend on the context of the sentence and the desired effect the writer wishes to convey.