demonstrative

adj. 1 showing feelings readily; affectionate. 2 (usu. Foll. By of) logically conclusive; giving proof (demonstrative of their skill). 3 gram. (of an adjective or pronoun) indicating the person or thing referred to (e.g. This, that, those).  demonstratively adv. Demonstrativeness n.

a. Having the nature of demonstration; tending to demonstrate; making evident; exhibiting clearly or conclusively.