1. To make bigger; to increase the size of; to magnify. 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: embiggen, smallify
"Gentlemen. We must biggify our endeavors."
"That font looks kinda small. You should biggify it."