"Sideloaded" means to install or add software or applications on a device from a source other than an official app store or authorized channel. Full definition
RIM is planning to disable support for sideloaded apps on its BlackBerry PlayBook with a forthcoming update. (slashgear.com)
The microSD slot gives you flexibility in sideloading books in various formats. (pcmag.com)
New users might struggle with the concept of sideloading in their own books or even knowing on where to download them from the internet. (goodereader.com)