Green’s Dictionary of Slang

patent gentry n.

[ety. unknown; ? pun on SE]

(US) cheating gamblers.

Jeffersonian (Kosciusko, MS) 23 Nov. 2/3: In ‘all fours,’ or the game of ‘old sledge,’ as it is called, he illustrated the frauds which the ‘patent gentry’ have over those who play depending on their own judgment.