According to the Merriam-Webster dictionary, bully means: "One who is habitually cruel to others who are weaker."
Basically, bullying is when someone is being mean to others who don't have as much power as them. There are four forms of bullying.
1) Physical: hitting, kicking, pinching, punching, scratching, spitting or any other form of physical attack. Damage to or taking someone else’s belongings may also constitute as physical bullying.
2) Verbal: Name-calling, insulting, making racist, sexist or homophobic jokes, remarks or teasing, using sexually suggestive or abusive language, offensive remarks. This is the most common form of bullying.
3) Cyber: any type of bullying that is carried out by electronic medium such as :
- Text message bullying
- Picture/video clip bullying via mobile phone cameras
- Phone call bullying via mobile phones
- E-mail bullying
- Chat-room bullying
- Bullying through Instant Messaging (IM)
- Bullying via websites
4) Emotional: spreading nasty stories about someone, exclusion from social groups, being made the subject of malicious rumours.