There are several synonyms for the phrase "orders to testify". One commonly used term is "subpoena". A subpoena is a legal order that requires an individual to testify in court or provide evidence. Another synonym is "summons". A summons is similar to a subpoena but may also be used to notify someone of a court appearance or to provide documents. "Writ of mandamus" is another synonym that refers to a court order that requires someone to perform a certain act, such as testifying. Finally, "court order" itself can be used as a synonym as it encompasses any legally binding directive issued by a court.