Flatwise is a 8 letter English word. It's valid Scrabble word worth 14 points. It's valid Words with friends word worth 15 points.
You can make 381 anagrams from letters in flatwise (aefilstw).
First recorded in 1595-1605; flat1 + -wise
Placing it flatwise on supports close to its ends we find that its own weight causes a decided sag.