Green’s Dictionary of Slang

1. the vagina; thus, women in the context of potential seduction.

2007

C. Goffard Snitch Jacket 70: Then I remembered a coño is a pussy.

2. as a general insult.

1995		C. Hiaasen Stormy Weather 189: I will find you, coño.
2012		J. Díaz This Is How You Lose Her 155: Say hello, coño, to la profesora.