Source : Webster's Revised Unabridged Dictionary (1913)

Interrogative \In`ter*rog"a*tive\, a. [L. interrogativus: cf. F.
   interrogatif.]
   Denoting a question; expressed in the form of a question; as,
   an interrogative sentence; an interrogative pronoun.

Interrogative \In`ter*rog"a*tive\, n. (Gram.)
   A word used in asking questions; as, who? which? why?

Source : WordNet®

interrogative
     adj 1: relating to verbs in the so-called interrogative mood; "not
            all questions have an interrogative construction"
     2: relating to the use of or having the nature of an
        interrogation [syn: {interrogatory}, {asking(a)}] [ant: {declarative},
         {declarative}]

interrogative
     n 1: a sentence of inquiry that asks for a reply; "he asked a
          direct question"; "he had trouble phrasing his
          interrogations" [syn: {question}, {interrogation}, {interrogative
          sentence}]
     2: some linguists consider interrogative sentences to
        constitute a mood [syn: {interrogative mood}]