Green’s Dictionary of Slang

1. stubborn, tough, uncompromising.

1927		K. Nicholson Barker III i: If she comes to say goodbye, don’t be hardnosed. Treat her decent.
1952		J. Jones From Here to Eternity (1998) 328: Falling for a hard nosed whore at Mrs Kipfer’s. That was just about that punk’s goddam speed.
1959		A. Zugsmith Beat Generation 25: Man, you’re hard nose!
1960		G. Swarthout Where the Boys Are 94: Men from the Big Ten are so hardnosed around anyone from the League.
1962		H.S. Thompson letter 16 Feb. in Proud Highway (1997) 321: I finally wrote him a very hardnose letter at his home.
1975		E. Torres Carlito’s Way 13: My buddy was hard-nose.
1978		Observer Mag. 14 May 53: Officer Spottke is known as a cop’s cop: tough, hard-nosed, good in a fight.
1987		T. Wolfe Bonfire of the Vanities 370: Or if they really want to get hard-nosed about it, they could work on a theory of assault with a dangerous weapon.
1994		N. McCall Makes Me Wanna Holler (1995) 151: From the hardest-nosed thugs to the most bombed-out junkies.
2000		Indep. Rev. 25 Feb. 13: Hard-nosed business man Hereman Blume [...] is drawn to Max’s icy ‘can-do’ attitude.
2022		G.M. Graff Watergate 130: [T]he well-respected and hard-nosed Richard McLaren.

2. common-sense, sensible, e.g. hard-nosed practicalities.

1984		Partridge DSUE (8th edn) 531: [...] 1970s.
1999		Indep. on Sun. Culture 22 Aug. 2: A working-class background [...] taught him a hard-nosed attitude to money.