Green’s Dictionary of Slang

matey adj.

friendly.

1915		T. Burke Nights in Town 206: A little drop of port for the missus – ‘just by way,’ as he explained, ‘of being matey’.
1923		Wodehouse Leave it to Psmith (1993) 582: He seemed such a dashed matey sort of bird.
1930		M. Allingham Mystery Mile (1982) 371: What’s to prevent my killing you, as soon as we stop being matey?
1941		K. Tennant Battlers 100: These boangs are all too matey.
1954		(con. 1940s) T.A.G. Hungerford Sowers of the Wind 35: You two seemed damned maty [...] You and the Jap.
1967		F. Sargeson Hangover 153: Booze [...] makes you feel matey – and oh yes, two senses intended.
1976		P. Theroux Family Arsenal 232: He’s just trying to be matey.
1982		G. Newbold Big Huey 158: The Copper was relieved that for once we weren’t getting at him, and he got all matey again.
1999		Guardian Guide 12–18 June 10: The blokey, matey [...] contingent.
2012		A. Prentice ‘The Break’ in Crime Factory: Hard Labour [ebook] Matt didn’t respond to the matey crap, just told them what had happened.