Green’s Dictionary of Slang

1. depressed.

1645		F. Quarles Solomon’s Recantation in Complete Wks (1880) 174/2: Why then my soul, Goe winde the Plummets up Of thy down spirits .
1700		N. Ward London Spy XV 359: He describes a Swarthy, Black Ill-looking Fellow, with a down-look, or the like [...] such sort of Rogues are seldom without a Gallows in their Countenances.
1879		J. Payn ‘Number Forty-Seven’ in High Spirits III 82: ‘Well, he was rather a down-looking cove.’ ‘Hang-dog?’ said I. ‘Well, yes.’.
1970		L. Sanders Anderson Tapes 217: I wasn’t feeling down. I was feeling up. I thought it had been a very successful evening.
1981		S. Berkoff Decadence in Decadence and Other Plays (1985) 8: You ask me the cause for my down face / wait till you hear what I have to say.
2000		W.D. Myers ‘Block Party–145th Street Style’ in 145th Street 140: The closer the wedding got the more down she was.

2. (drugs) currently not under the infleunce of a drug [the antithesis of high adj.¹ (3)].

1964		H. Selby Jr. Last Exit to Brooklyn 34: [S]he had nothing except the benzedrine which would probably be found and thrown away. There was [...] no way she could get it. In the house a week or more with nothing. I’d crack. I cant stay down that long. They'll bug me. Bug me. O jesus jesus jesus.
2012		(con. 1943) G.S. Manson Coorparoo Blues [ebook] Jack was still sparking from the bloody pills, but he knew he was going to go down like tall timber before very long.

3. depressing.

1972

New Yorker 5 Aug. 21: It’s too down. I don’t like down movies. I like up movies.