slang. [f. BOSH sb.3] trans. To make of no effect; to spoil; to humbug.
1870. Macm. Mag., XXI. 71. You ‘bosh’ his [a man’s] joke by refusing to laugh at it; you ‘bosh’ his chance of sleep by playing upon the cornet all night in the room next to him.
1883. Miss Braddon, Gold. Calf, xiv. Boys would get on capitally with Jardine. They’d never try to bosh him.
