a.

1. 思索的；推测的
   Much of our information is speculative.

   我们的许多信息是带推测性的。

   Due to the speculative nature of the evidences, the judge could not arrive at a concrete decision.

   因为所有的证据都是推测性的，法官无法作出具体的结论。

2. 纯理论的，非实用性的
3. 冒险性的，不确定的
4. 投机的；好投机的
   speculative ventures in real estate

   房地产投机生意

adj.

1. engaged in, expressing, or based on conjecture rather than knowledge.
2. (of an investment) involving a high risk of loss.