1 ° _ container to store a product, usually edible, although it can be any other that should be kept without spread (as a jar of nails). 2nd _ in lunfardo is fortune, "jar" is "luck". It comes indirectly from "housewives of milk", said that they are breastfeeding with 'good' or 'nasty' and that changed the character of the baby. Was happy who had "good milk", because having milk also was feeling lucky; and when it began to be sold in jars, "a jar of milk" was very lucky. Then he was simply "having jar". See ass. 3rd _ in slang is also shoe, although most used in the plural.
