speculative Syllabification: (spec·u·la·tive)Pronunciation: /ˈspekyəˌlātiv, -lətiv/Translate speculative | into German | into Italian | into Spanish Definition of speculative adjective 1engaged in, expressing, or based on conjecture rather than knowledge:discussion of the question is largely speculative 2(of an investment) involving a high risk of loss. (of a business venture) undertaken on the chance of success, without a preexisting contract. Derivatives speculatively adverb speculativeness noun speculative in other Oxford dictionaries Definition of speculative in the British & World English dictionary