Tending to show feelings, especially of affection, openly. She was very demonstrative, always hugging and expressing her love for her friends.
Serving as conclusive evidence of something; giving proof. The demonstrative evidence presented in court left no doubt about the defendant's guilt.
Relating to or constituting a class of determiners (such as ‘this’, ‘that’, ‘these’, and ‘those’) that indicate which entities are being referred to. In the sentence ‘That book is mine’, ‘that’ is a demonstrative determiner.