I believe this is a food.

I found this that may help: Popovers and Split Views Across the iPad system, Apple has introduced a new UI element, which they’re calling popovers. It’s a perfect name. Popovers are like a cross between dialog boxes, drop-down menus, and inspector palettes. One example is the list of mailboxes in Mail when in vertical mode. When iPad Mail is in horizontal mode, you see a split view with two panels at once: accounts/mailboxes/messages on the left, and an always-present message detail panel on the right. When iPad Mail is in vertical mode, you just get one panel, but you can tap a button at the top left to show a popover of messages in the current mailbox. From http://daringfireball.net/2010/01/various_ipad_thoughts

Elle is correct, I think a "popover" is a type of bread, like a fluffy roll. In the southern United States, we may also say "I am going to 'pop over' to someones house," meaning we will go for a short visit to that person.

oh yeah, but in the context i wanna know is in a iOS development, cause there is a time they use this word to refer to some functionality.