Source : Webster's Revised Unabridged Dictionary (1913)

Interrogatory \In`ter*rog"a*to*ry\, n.; pl. {Interrogatories}.
   [Cf. F. interrogatoire.]
   A formal question or inquiry; esp. (Law), a question asked in
   writing. --Macaulay.

Interrogatory \In`ter*rog"a*to*ry\, a. [L. interrogatorius.]
   Containing, expressing, or implying a question; as, an
   interrogatory sentence.

Source : WordNet®

interrogatory
     adj : relating to the use of or having the nature of an
           interrogation [syn: {interrogative}, {asking(a)}] [ant:
            {declarative}, {declarative}]
     n : formal systematic questioning [syn: {interrogation}, {examination}]