1. To make smaller; to decrease the size or scope of. Not a standard word; often used for the humor derived from the fact that it mimics the sound of other real, often technical-sounding words ending in -fy, such as "magnify," "rarefy," "terrify," and "mollify."
Compare: biggify, embiggen
"Whoa whoa whoa, this picture is way too big. Smallify that shit, please."
"We decided to smallify the layout of the room."
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.