subpoena ad testificandum
noun
subpoena ad tes·ti·fi·can·dum -ˌad-ˌte-stə-fi-ˈkan-dəm 
: a writ commanding a person to appear in court to testify as a witness
Word History
Etymology
New Latin, under penalty to give testimony
First Known Use
1594, in the meaning defined above
Legal Definition
subpoena ad testificandum
subpoena ad tes·ti·fi·can·dum
-ˌad-ˌtes-tə-fə-ˈkan-dəm, -ˌäd-ˌtes-tē-fē-ˈkän-ˌdu̇m
: a subpoena that commands a witness to appear and give testimony