a device, an expedient.
|Hist. of Lady J. Mandeville 31: Poor fellow! I pity him; but marriage is his only card.|
|Woodstock III 358: No card seemed to turn up favourable to the royal cause.|
|Digby Grand (1890) 231: [of a horse] ‘Polly’s the card for you to stick to, ain’t she, Grand?’.|