Doesn't have wings
Doesn't breathe fire
Doesn't fly
Doesn't roar
Isn't bigger than a house
Some dragons don't have wings. (Asian dragons, leviathans, wyrms)
Some breath ice
Leviathans don't fly, it can be classified as a "dragon"
Some dragons chirp instead of roaring.
Some full grown dragons aren't that big.
But then again "YOU HAVE NOT SEEN ONE HOW CAN THINGS YOU SAY BE TRUE?"