An acquaintance that you invite to important functions such as weddings and baby showers, but wouldn't normally hang out with otherwise. Like a carnation is a filler flower in a bouquet, the filler friend gives out the illusion that you have more friends than you actually do.
Since my fiance invited all of his hockey team to our wedding, I sent out an invitation to all of my filler friends so that I won't look like a loser with no friends at my wedding.
