tending to exaggerate; involving or characterized by exaggeration.

What is the meaning of Exaggerative?

exaggerative in American English

(ɪɡˈzædʒəˌreitɪv, -ərətɪv) adjective. tending to exaggerate; involving or characterized by exaggeration. Also: exaggeratory (ɪɡˈzædʒərəˌtɔri, -ˌtouri)

Is over Exaggerative a word?

No. The Oxford Dictionaries doesn't recognize overexaggerate as a word. In fact, if you search for overexaggerate in this dictionary, you won't find an entry for it.