Forced marriage is when you are made to marry someone against your will. It is illegal, so usually happens in secret.
It is different to an arranged marriage where both people consent. In the UK, the minimum age to marry is 16.
Some families may force you to marry as part of your religion or culture and may tell you it is the right thing to do - it is not.
They may tell you that if you do not go through with it you will bring shame on them - this is emotional abuse.
If this is happening to you, or someone you know, get help.