Loser (plural losers) –

1. A person who loses; one who fails to win –
2. Something of poor quality –
3. A person who is frequently unsuccessful in life –
4. A unfashionable person –
5. A person who loses something –

Bullying is the use of force, threat, to abuse, intimidate, or aggressively dominate others.

Behaviors used to assert such domination can include verbal harassment or threat, physical assault.

Rationalizations of such behavior include differences of social class, sexual orientation, race, religion, gender, appearance, behavior, body language, personality, reputation, lineage, strength, size, or ability.

If Bullying is done by a group, it is called mobbing.