dum-dum
n.— «When he returned in ’03, McLain was equipped with a thick cushion to wear atop his helmet (he refers to it as a “dum-dum”), which softened any potentially dangerous blows to the head.» —“McLain Making Progress” by Mitch Dobbs ‘Bama (Al.) June 24, 2004. (source: Double-Tongued Dictionary)
Further reading
If you speak a second or third language, you may remember the first time you dreamed in that new tongue. But does this milestone mean you’re actually fluent? And a couple’s dispute over the word regret: Say you wish you’d been able...
An anadrome is a word that forms a whole new word when you spell it backwards. For example, the word “stressed” spelled backwards is “desserts.” Some people’s first names are anadromes. There’s the girl named Noel...