Green’s Dictionary of Slang

an expletive; also as a general derog. adj.

1928		C. McKay Home to Harlem 130: ‘Bumbole’ was now a popular expletive for Jake, replacing such expressions as ‘Bull,’ ‘bawls,’ ‘walnuts,’ and ‘blimey.’ Ever since the night at the Congo when he heard the fighting West Indian girl cry, ‘I’ll slap you bumbole,’ he had always used the word. When his friends asked him what it meant, he grinned and said, ‘Ask the monks’.
1929		C. McKay Banjo 296: Ain’t a bumbole thing delicate about a man being perticular what he’s putting away in his guts.