Green’s Dictionary of Slang

dirt nap n.

(US black) death; also attrib.

implied in take a dirt nap
[US]Lewin & Lewin Thes. Sl. 93/2: Death [...] dirt nap.
[UK]J. Mowry Way Past Cool 133: Pussy little faggot gun be shootin pussy little bullets, meanin dirt-nap time for assholes what don’t shut the fuck up.
[US]J. Stahl Plainclothes Naked (2002) 217: Anybody dumb enough to give somethin’ worth a million bucks to somebody else deserves a dirt nap.
Death Clock Obituaries 🌐 Well, no matter how much money or good looks you have, everyone takes the dirt nap eventually, and now you can plan ahead with the Death Clock Obits.

In phrases

take a dirt nap (v.) (US black)

1. to be buried.

[UK]C. Quigley Corpse 20: Once put to bed with a shovel, the dead can do nothing but take a dirt nap in a bed of clay.
[US]K. Norton et al. Going the Distance 20: Retire after 30 years, collect my pension, pick out my burial plot and casket, and take a dirt nap.

2. to die; to be killed.

Meek Mill ‘A1 Everything’ 🎵 Sleep on me if you wanna take a dirt nap.
Twitter 6 June 🌐 I reckon Comrade Commissar Putin will be taking a dirt nap pretty soon.

3. (also do the dirt nap) to die.

Bosom Buddies [ABC-TV] We’ve got to convince him that Hildy’s taken a dirt nap [HDAS].
[US]R.A. Spears Contemp. Amer. Sl. 208: take a dirt nap tr. to die and be buried. ? I don't want to end up taking a dirt nap during this operation.
Angela posting 14 Sept. at SLOLane.org 🌐 Make that Goodwill Modern with assloads of debt and new appliances, because the latest major appliance to take a dirt nap in a long string of mechanical deaths this month include the dishwasher, as of yesterday. With the amount of housework we are already doing with two babies around, you can imagine how long it took us to think about getting a new one. About two seconds.
posting at thinkprogress.org 11 Oct. 🌐 You’re a bunch of pathetic treasonous vermin and I hope one day to see the lot of you do the air dance and the dirt nap.