A more thorough explanation:

Term: In campo
Definition: In campo means "in the field" or "before the court" in Latin. It refers to being present and actively involved in a legal case or dispute.
Examples:

• The lawyer was in campo during the trial, arguing for his client's innocence.
• The judge asked the witness to testify in campo, meaning they had to come to court and give their testimony in person.

These examples show how in campo is used to describe someone's involvement in a legal case. The lawyer and witness are both actively participating in the trial, either by arguing or testifying in person.