A little pest who likes to burst into your room while your doing homework, or playing on your phone. They like to hit you, then like a little bitch, they tell your parents when you hit back. In other words...they are annoying. They are so annoying they make you feel like banging your head against the wall so hard you lose all your brain cells.
You: *on your phone*
Younger sibling: *bursting into your room and runs up to you* Hey!
You are playing COD and u die
Me FUCK
little sibling: FUCK
Then ur mum walks in and grounds u for a month for teaching sibling swears. You see little sibling gripping mums leg and sneering at u.