opin·a·tive I. \ōˈpinəd.iv\adjective Etymology: Late Latin opinativus expressing a conjecture, from Latin opinatus (past participle of opinari) + -ivus -ive 1.obsolete: obstinate, opinionated 2.: of, relating to, or constituting opinion : uncertain • opinativelyadverb, obsolete II. noun (-s) : an opinionated person