Green’s Dictionary of Slang

1. to spend money extravagantly.

1839		Northern Star (W. Yorks) 28 Sept. 4/2: That rattling, splashing, dashing [...] leather-headed, good-for-nothing kind of a fellow.
1886–96		Marshall ‘Pomes’ from the Pink ’Un 8: I don’t want a shiner that’s only splashed [F&H].
1903		‘Hugh McHugh’ I Need The Money 13: I traveled with the Andrew Carnegie push and tried to give my coin away, but I’m through. I’ve stopped splashing.
1907		Sun. Times (Perth) 21 Apr. 4/8: Having pawned the jewellry he hired a cab, and, along with two gorgeous ladies, splashed up the proceeds with liberal fist.
1916		C.J. Dennis ‘Duck an’ Fowl’ in Moods of Ginger Mick 16: Ginger calls fer Rosie, an’ to celerbrate ’is win / ’E trots ’er down to Ah Foo’s joint to splash a bit uv tin.
1941		F. Sargeson ‘That Summer’ in Coll. Stories (1965) 173: After we’d splashed on a talkie we went home.
1959		A. Sillitoe ‘Loneliness of the Long-Distance Runner’ Loneliness of the Long-Distance Runner (1960) 24: We’ve got months to splash the lolly.
1969		R. Rendell Best Man To Die (1981) 26: Thanks to Charlie boy, they’d been able to splash a bit on the wedding.
1999		Guardian Guide 14–20 Aug. 29: They can afford to splash a few quid to get their man.
2001		A. Sillitoe Birthday 155: There’s no need to splash fifty quid on a meal.

2. (Aus.) to hit (hard enough to elicit blood).

1904

Sydney Sportsman (Surry Hills, NSW) 21 Dec. 1/3: The pug barracker, who rips the atmosphere into small strips with yells ol ‘Splash him,’ ‘Tear into him,’ etc.,.

3. to masturbate.

1984

Partridge DSUE (8th edn) 1128/1: since ca. 1930.

4. (US) for a boxer to lose a fight voluntarily, usu. in return for payment [play on take a dive under dive n.¹ ].

1947

B. Schulberg Harder They Fall (1971) 205: He’ll tell that nigger what’ll be if he don’t splash this round.

5. (US black) to achieve orgasm; to ejaculate.

2014		T.I. ‘About My Issue’ 🎵 Just ride this till you get to splash / You a wild girl, go cowgirl / Keep the noise down, you loud girl.
2015		67 ‘Skengs’ 🎵 My thottie’s a peng she opens her mouth and I splash in her throat.

6. (UK Black) to stab (to death).

2017		1011 ‘No Hook’ 🎵 Teewizz got splashed and got murdered.
2018		Unknown T ‘Mad about Bars’ 🎵 One lickle ching and they chat like kids / He got splashed, and he got cheffed.
2018-20		T. Thorne (ed.) ‘Drill Slang Glossary’ at Forensic Linguistic Databank 🌐 Splash, splash up, splash down - stab.