Green’s Dictionary of Slang

1. (W.I., also sweet up) to please.

1793		J.B. Moreton West India Customs and Manners 157: Tajo, tao, tajo! my mackey massa! [...] I’ll please my mackey massa! I’ll jig to mackey massa! / I’ll sweet my mackey massa!
1862		Capt. Clutterbuck’s Champagne 260: My king! it must have sweet* her to be save dat way. [...] *Delighted.
1942		L. Bennett ‘Married’ in Jam. Dialect Poems 28: But she no care bout dad, what sweet her / Is de ‘money’ part.
1955		R. Mais Black Lightning (1966) 34: ‘Don’t feel like it,’ said Amos, huffily, ‘it don’t sweet me any more.’.
1994		M. Montague Dread Culture 48: Yuh a go inside fi sweet up Harry.

2. (US Und.) to lose.

1791

‘Flash Lang.’ in Confessions of Thomas Mount 19: To lose, to sweet.