Subway has released a statement declaring that their footlong subs are only 11 inches long, because "footlong" isn't supposed to be a measurement of length.  Which sounds ridiculous, but here are six other things with names that don't describe what they really are:          

#1.)  If you buy a TWO-BY-FOUR at the lumber store, it's not really two inches by four inches… it's one-and-a-half inches by three-and-a-half inches.

#2.)  PEANUTS aren't really nuts . . . they're legumes.  

#3.)  A KOALA BEAR isn't a bear . . . it's a marsupial, like a kangaroo.

#4.)  A STARFISH isn't a fish . . . it's something called an echinoderm.

#5.)  A PALM TREE isn't actually a tree.  It's a type of grass.

#6.)  And if you have SWOLLEN GLANDS, your glands aren't swollen . . . your lymph nodes are.

(NPR)