Green’s Dictionary of Slang

1. (US) aggressive, tough.

1902		Houston Dly Post (TX) 1 June 31/7: A bulldog of the rough-necked and low-browed variety. The teeth of this dog protrude and there is a fierce gleam in his little red eyes.
1912		Seattle Repub. (WA) 4 Oct. 2/3: The American soldier is generally a pretty decent fellow [...] while there some rough-necked irresponsible and disreputable people among them.
1915		Van Loan ‘The Spotted Sheep’ in Taking the Count 103: I’ve half a notion to write this roughneck saloon keeper and tell him to bring his man down.
1919		in A. Cornebise Amaroc News (1981) 3 Sept. 127: They say he’s just a roughneck brute, in a khaki suit, a regular army man.
1920		C. Sandburg ‘Smoke and Steel’ in Smoke and Steel 7: The others were roughneck singers a long ways from home.
1947		R.O. Boyer Dark Ship 147: He’s just a roughneck sailor.
1970		in P.R. Runkel Law Unto Themselves 263: You mean that broad of yours, the roughneck blonde?
1979		D. Maitland Breaking Out 169: You are a bloody lop-eared [...] rough-headed [...] fart-faced flip of a fucking galah!
1986		R.G. Barrett Godson 165: Several rough-headed locals were quietly drinking their beers.
2004		London Posse ‘Money Mad’ 🎵 Could be a kiter, a dipper, a blagger / Or a roughneck ragga brandishing a dagger.

2. a general pejorative.

1913		H.A. Franck Zone Policeman 88 86: But a bachelor is a bachelor on the Zone, and though he be clerk to his highness ‘the Colonel’ himself he may find himself carelessly tossed into a ‘rough-neck’ brotherhood.
1920		S. Lewis Main Street (1921) 389: They all got lit up like a White way, and went out to a roughneck dance.
1931		W.N. Burns One-Way Ride 285: Just a happy-go-lucky, roughneck West Side kid.
1977		S. Berkoff East in Decadence and Other Plays (1985) 73: All those rough-necked Irish bog-diggers.
1997		Simon & Burns Corner (1998) 42: Chin riveted to his chest, arms stiff at his sides, he moves with his practised roughneck walk.
1999		Guardian Guide 29 May–4 June 40: A rough-necked and oft-drunken companion.

3. excellent, admirable, very good [on bad = good model].

2000		N. Barlay Crumple Zone 68: Some homegrown roughneck soldier straight off the Grove front line.
2002		‘Touré’ Portable Promised Land (ms.) 156: We Words (My Favorite Things) [...] Bumrush. Baadasss. Buckwild. Hepcat. Freestyle. Roughneck.