Green’s Dictionary of Slang

1. an Irishman; thus Patrick O’Flynn, a beggar who imitates a stereotypical Irishman.

1832		Spirit of the Times (NY) 14 Apr. 4/1: An Irishman [...] landing at Philaelphia was assisted on shore by a negro who spoke to Patrick in Irish.
1846		D. Corcoran Picking from N.O. Picayune 107: A wag, who knew an irishman to be sick in the hospital, was determined to have a joke at the expense of poor Patrick’s wife’s feelings.
1884		San Antonio Light (TX) 16 Oct. 4/3: He looked over to where a well-to-do Irish-man was sitting. ‘Well, Patrick, how much have you got laid up against a rainy day?’.
1889		Clarkson & Richardson Police! 236: ‘Patrick O’Flynn’ [...] His get-up in Irish costume is perfect, and, with his blackthorn, he visits public-houses, where he sings Irish songs and gives Irish comic recitations.
1958		(con. 1940s) B. Behan Borstal Boy 255: Read the life of your distinguished fellow-Patrick.

2. (US black) a red-haired man, usu. in context of a prostitute’s client [pun on Pat n. (1) + play on trick n.¹ (3)].

2000

Ebonics Primer at www.dolemite.com 🌐 patrick Definition: a red haired trick. Example: Let that Patrick suck yo dick for good luck.