A moustache grown while on a military deployment. The term is used most commonly by US Marines, as it is the only facial hair allowed by regs. Also, if you're gonna grow a stache and look like a stalker, you might as well do it while on a det, so your family doesn't have to see you like that.
Shim: "How come Jethro is lookin' all creepy these days?"
Dirty: "Yeah, now that his det stache is filling in, he kinda looks like a child molester."
Frumba: "Tom Selleck made it cool in the 80's; my det stache brings the awesomeness today."
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