(1):
(a.) Expressing, or apt to express, much; displaying feeling or sentiment; as, her nature was demonstrative.
(2):
(a.) Consisting of eulogy or of invective.
(3):
(n.) A demonstrative pronoun; as, "this" and "that" are demonstratives.
(4):
(a.) Having the nature of demonstration; tending to demonstrate; making evident; exhibiting clearly or conclusively.