klutz
A person who is often clumsy and has little coordination.
A klutz is someone who frequently trips, drops things, bumps into furniture, or has other clumsy accidents. If you're carrying a tray of dishes and somehow manage to stub your toe, wobble sideways, and send everything crashing to the floor, someone might laugh and call you a klutz.
The word is usually used affectionately rather than meanly. When your friend spills juice for the third time at lunch, you might tease them by saying, “You're such a klutz!” but you'd say it with a smile while helping clean up. Many people feel klutzy in certain situations: maybe you're graceful on a soccer field but turn into a total klutz in dance class.
Being a klutz doesn't mean you're careless or not trying. Some people's bodies just don't always cooperate with what their brains want them to do. They might knock over a glass while reaching for the salt, or trip over their own shoelaces even when they're tied. Growth spurts can make kids temporarily klutzier because their arms and legs have gotten longer and they haven't adjusted yet.