Green’s Dictionary of Slang

(US) very, extremely, a general intensifier.

1888		Congressional Record 3 Oct. 9122/1: He is way below, he is only 50 in mathematics [DA].
1905		R. Beach Pardners (1912) 41: Hold up! Your dope sheet is way to the bad.
1932		R. Fisher Conjure-Man Dies 235: Got a heavy date and I’m way late.
1949		‘Hal Ellson’ Duke 130: I’m feeling cool as hell [...] I’m way up.
1959		A. Anderson ‘Comrade’ in Lover Man 142: I know Frank De Voe from way back.
1967		A. Baraka Tales (1969) 10: ‘Woe, Rick you’re way,’ extending his hand, palm upward. [Ibid.] 19: I saw that ol’ fagit Bobby Hutchens [...] with a real D.C. queer. I mean a real way-type sissy.
1970		D. Ponicsan Last Detail 2: Bad-Ass, wake up, it’s way the hell past reveille.
1989		C. Hiaasen Skin Tight 88: Mick, what are you doing way the fuck out here?
1996		(con. 1964-65) B. Thorpe Sex and Thugs and Rock ’n’ Roll 157: Prescott looked like something out of a James Dean movie, and way cool.
1999		Indep. Rev. 28 July 4: Johnny Depp has typed a way cool tone poem.
2005		P. Howard Curious Incident of the Dog in the Nightdress 14: Or were you too busy looking around for other girls to impregnate? which is way harsh, it has to be said.
2006		G. Iles Turning Angel 163: Like breast implants. Way too big.
2007		L. Redhead Cherry Pie [ebook] ‘She was way cool’.
2017		Advocate & Messenger (Danville, KY) 20 Jan. A04/1: Our youth minister always thinks to herself, ‘way cool!’.
2021		J. Ellroy Widespread Panic 78: ‘It looks like a hot-prowl 459, gone way bad’.
2021		P Howard Braywatch 80: Sophie’s like, ‘No! Way!’ But Chloe’s there, ‘Way!’.