A more thorough explanation:

Definition: Ex capite metus is a Latin term used in Scots law to refer to a situation where a transaction is induced by serious threats. It means "on the ground of fear".

Example: If someone threatens to harm you or your family if you don't sign a contract, and you sign the contract because of that fear, the contract can be rescinded on the grounds of ex capite metus.

This means that if someone uses fear or threats to force you into a transaction, that transaction can be cancelled or rescinded. The law recognizes that people should not be forced into making agreements against their will, and that fear is not a valid reason to enter into a contract.