The watery substance that comes out of an unshaken ketchup bottle before the ketchup comes out in full force.
Damn! You got my fries all soggy with preketchup, don't you ever shake up the bottle.
The runny liquid that comes out of the ketchup bottle before the thicker, actual ketchup comes out.
Aw, man, I didn't shake the ketchup bottle before I poured it on my hotdog, and now there's pre-ketchup all over it.
The watery junk that often first comes out of plastic ketchup bottles.
Better shake that up or you'll get all that pre-ketchup on your burger.