subpoenaing

from The Collaborative International Dictionary of English v.0.48

Subpoena \Sub*poe"na\, v. t. [imp. & p. p. {Subpoenaed}; p. pr.
   & vb. n. {Subpoenaing}.] (Law)
   To serve with a writ of subpoena; to command attendance in
   court by a legal writ, under a penalty in case of
   disobedience.
   [1913 Webster]