What is "con permiso" in English?
"Con permiso" translates on a word for word basis as :with permission".
However, "con permiso" is an accepted idiom. Idioms tend to defy word for word translation.
"Con permiso" tends to mean that the speaker knows what they want to do is usually considered to be bad manners, but, with the subjects permission the act becomes OK. At a personal experience, the serving staff (waiters and waitresses) asked "con permiso" before reaching in front of the table guests with the food they were serving. Also, the busboys and busgirls, asked "con permiso" before clearing away the used dishes and flatware.
The idiom "con permiso" tends to translate as "If I may"/"If you will excuse me"/ or more simply "Excuse me".
Con permiso is something you ask like when you are in a store and you want to pass someone. That's what you'd say to them. Or if you are reaching across someone (which is very rude, by the way) to get something, you'd say con permiso.
Also if you have seen Pirates of the Carribean you will remember the phrase "by your leave". It could mean that as well. (not a literal translation though)
To look this up, just click on the tab that says Translation. Enter the words and it will give you the English translation. Try it! It's very easy!