Definition
The word "dumdum" has two distinct meanings: it can refer to a person considered foolish or stupid, or it can refer to a type of bullet. As an insult, calling someone a "dumdum" is like calling them an idiot or a moron. ðĪĶ It's not a nice thing to say, implying someone lacks intelligence. The bullet meaning is more technical, referring to a bullet designed to expand on impact, causing greater damage. It is best to not use the insult. The other meaning is related to military history.