sub·poe·na 
(sə-pēnə)
(sə-pēnə)n.
An order issued under the authority of a court, commanding a person to appear in court on a particular date, usually to give testimony in a legal case.
tr.v. sub·poe·naed, sub·poe·na·ing, sub·poe·nas
To serve or summon with such a writ.
[Middle English suppena, from Medieval Latin sub poenā, under a penalty (from the opening words of the writ) : Latin sub, under; see SUB- + Latin poenā, ablative of poena, penalty; see kwei-1 in the Appendix of Indo-European roots.]