The World's Grayt'st Sentence!

"THE GREASIEST, MOST DELICIOUS, MOST LUCIOUS, MOUTH-WATERING, FLAVOR-BURSTING FLAT LONG BURGER IS THE BURGER OF ALL BURGERS."

The AUTHOR shall, upon a Whimsy of Devilry, leave it to you, READER, to Compense the meaning of the Frase: "flat long".