In the Northeastern U.S.: A colloquialism for the female vagina, often used with a negative connotation (i.e., smelly or dirty), although not always. Particularly common among the Italian-American communities of New England, where it developed as a calque for "baccalà " in Neapolitan (or vise-versa).
Example 1:
Aaron: Hey, how's this outfit look for the party tonight? I'm hoping to bring home a fox tonight.
Jake: Jesus Christ Aaron, what the f*ck are wearing? I'll tell you this: you're not catching ANY cod tonight wearing those date-rape slacks, that's for sure!
Example 2: (in town, at a night club)
Big-Paul: Hey Tony, you see that broad that just leff with Nico?
Tony: Yeah, whadda 'bout 'a?
Big-Paul: Kid, that's John-John's ex-girl.
Tony: Oh man, wasn't she some sorta, like, wicked puttana or somthin'?
Big-Paul: Yeah. Dude, he tole me that her cod smelt like fu**in' open ass an' that that's why they broke up in the firs place.
Tony: Aw, poor fu**in' Nico! I wonde' ha long it takes 'em te figure out she's packin' baccalà !
Tony & Big-Paul: Haaaa hahahaha!