Beyond numerary, esoteric meanings and "angle-shaped fabric tears", in lunfardo 'seven' is used to name the "ass". A believable etymology is brought by the trick game, which uses a Spanish deck and one of the luckiest hauls is the one known as "the big seven" (sign with a half smile to the right) which is when you play the seven of swords. Very few cards can beat you, and from here the "have the ass (luck) to play that card" is associated with the word buttocks, which is the original meaning of 'ass'. Another etymology with commonalities comes from the Neapolitan smorphy, where dreams about objects and situations are associated with numbers to bet on lottery games. There the 7 is "the jar" , which in some of its meanings is also "good luck" , the same as "have ass" . See taba , the big seven! , bad milk .
