speculativePronunciation: /ˈspɛkjʊlətɪv/Translate speculative | into German | into Italian | into Spanish Definition of speculative adjective 1engaged in, expressing, or based on conjecture rather than knowledge:he gave her a speculative glance 2(of an investment) involving a high risk of loss: the bonuses cannot be put at risk due to some speculative investment (of a business venture) undertaken on the chance of success, without a pre-existing contract: he was involved in speculative buildingDerivatives speculatively adverb speculativeness noun speculative in other Oxford dictionaries Definition of speculative in the US English dictionary