Green’s Dictionary of Slang

card of ten n.

[the image of bluffing in a card game, in which ten is only an average card]

a playing card image used fig. to denote an act of bluff.

Show quotations
[UK]Brinklow Complaynt of Roderyck Mors. (1874) 45: Eyther he shal haue fauor for his masters sake, or els bragg it owt with a carde of x .
[UK]Lyly Euphues and his England (1916) 302: All lovers (he only excepted) are cooled with a card of ten, or rather fooled with a vain toy.