Green’s Dictionary of Slang

1. (orig. US cowboy, then tramp) percolated coffee, as opposed to that boiled up in a pan.

1936		H.W. Bentley ‘Linguistic Concoctions of the Soda Jerker’ in AS XI:1 44: PERK. Percolated coffee.
1941		J. Smiley Hash House Lingo 42: Perk, coffee.
1960, 1975		Wentworth & Flexner DAS.

2. (US) a coffee percolator.

1934		F.E. Baily Fleet St Girl 59: Amazing coffee Charles makes in that electric perc [OED].
1945		Baker Aus. Lang.
1956		H. Gold Man Who Was Not With It (1965) 277: Boil up some coffee for my friends [...] But don’t try to use the perc, you’re too stupid.

3. (US drugs, also perky) the painkillers Percodan (aspirin + oxycodone) / Percocet ( acetaminophen and oxycodone).

1986		J. Ellroy Suicide Hill 239: [of Percodan] [T]he perk/dexie speedballs he'd eaten just before the one-on-one with the cop kept the pain down and juice in his system.
2012		M. McBride Frank Sinatra in a Blender [ebook] I scanned the glove box for any more medication that may have escaped my attention. I knew I hadn’t given the Perc’s enough time to do their job, but my face was sending out violent shockwaves of excruciating pain.
2017		Guardian 17 Nov. 5/1: ‘Pop a perky just to start up.’ [...] ‘Perky’ is Percocet, a painkiller made up of paracetamol and the opioid oxycodeine.
2019		N. Walker Cherry 157: Burnes and Borges said they’d take some Percs since I was offering.
2020		S.A. Crosby Blacktop Wasteland 59: He went over to Wonderland to score some Percs.