Definitions

1. noun

a short, dull, low-pitched sound, especially the sound of a drumbeat

“The drummer’s steady dum accompanied the march.”

2. verb

to make a dull, low-pitched sound, especially the sound of a drumbeat

“The drummer began to dum on his drum.”

3. interjection

an expression of boredom or lack of interest

“Dum, I’ve heard this story before.”