If someone is subpoenaed, they are given a legal order to go to court and give evidence.
Being subpoenaed can make people feel nervous or worried because it means they have to go to court.
Examples:
He was subpoenaed to testify in court.
She had to go to court because she was subpoenaed.
The witness was subpoenaed to appear in court.
I hope I never get subpoenaed to go to court!
The famous singer was subpoenaed to testify in the trial.
She was subpoenaed and had to go to court to tell what she knew.