The Collaborative International Dictionary of English v.0.48:

Inquisition \In`qui*si"tion\, n. [L. inquisitio : cf. F.
   inquisition. See Inquire, and cf. Inquest.]
   1. The act of inquiring; inquiry; search; examination;
      inspection; investigation.
      [1913 Webster]

            As I could learn through earnest inquisition.
                                                  --Latimer.
      [1913 Webster]

            Let not search and inquisition quail
            To bring again these foolish runaways. --Shak.
      [1913 Webster]

   2. (Law)
      (a) Judicial inquiry; official examination; inquest.
      (b) The finding of a jury, especially such a finding under
          a writ of inquiry. --Bouvier.
          [1913 Webster]

                The justices in eyre had it formerly in charge
                to make inquisition concerning them by a jury of
                the county.                       --Blackstone.
          [1913 Webster]

   3. (R. C. Ch.) A court or tribunal for the examination and
      punishment of heretics, fully established by Pope Gregory
      IX. in 1235. Its operations were chiefly confined to
      Spain, Portugal, and their dependencies, and a part of
      Italy.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Inquisition \In`qui*si"tion\, v. t.
   To make inquisition concerning; to inquire into. [Obs.]
   --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Inquisition
    n 1: a former tribunal of the Roman Catholic Church (1232-1820)
         created to discover and suppress heresy
    2: a severe interrogation (often violating the rights or privacy
       of individuals)

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "inquisition":
   Areopagus, analysis, assize, board, change of venue, council,
   court-martial, cross-examination, cross-interrogation,
   cross-questioning, curia, delving, direct examination, examination,
   forum, grilling, hearing, inquest, inquirendo, inquiring,
   inquiring mind, inquiry, investigation, judicatory, judicature,
   judiciary, jury trial, mistrial, police interrogation, probe,
   probing, quest, redirect examination, research, the Inquisition,
   the grill, third-degree, trial, trial by jury, tribunal



Bouvier's Law Dictionary, Revised 6th Ed (1856):

INQUISITION, practice. An examination of certain facts by a jury impanelled
by the sheriff for the purpose; the instrument of writing on which their
decision is made is also called an inquisition. The sheriff or coroner and
the jury who make the inquisition, are called the inquest.
     2. An inquisition on an untimely death, if omitted by the coroner, may
be taken by justices of gaol delivery and oyer and terminer. or of the
peace, but it must be done publicly and openly, otherwise it will be
quashed. Inquisitions either of the coroner, or of the other jurisdictions,
are traversable. 1 Burr. 18, 19.