Wiktionary
umming
vb. (present participle of um English)
Usage examples of "umming".
Penny Woertz snuggling against me in the night, her back and shoulders moist with exertion, making little umming sounds of content as her breath was slowing.
I saw Jinian’s eyes snap open to complete awareness, though Silkhands made only a drowsy umming sound and slept on.