The Collaborative International Dictionary of English v.0.48:

Declarative \De*clar"a*tive\, a. [L. declarativus, fr.
   declarare: cf. F. d['e]claratif.]
   Making declaration, proclamation, or publication;
   explanatory; assertive; declaratory. "Declarative laws."
   --Baker.
   [1913 Webster]

         The "vox populi," so declarative on the same side.
                                                  --Swift.
   [1913 Webster]

WordNet (r) 3.0 (2006):

declarative
    adj 1: relating to the use of or having the nature of a
           declaration [syn: declarative, declaratory,
           asserting(a)] [ant: interrogative, interrogatory]
    2: relating to the mood of verbs that is used simple in
       declarative statements; "indicative mood" [syn: indicative,
       declarative]
    n 1: a mood (grammatically unmarked) that represents the act or
         state as an objective fact [syn: indicative mood,
         indicative, declarative mood, declarative, common
         mood, fact mood]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "declarative":
   absolute, affirmative, affirmatory, annunciatory, assertative,
   assertional, assertive, decided, declaratory, emphatic,
   enunciative, heraldic, positive, predicational, predicative,
   proclamatory, promulgatory, publicational