- 1[uncountable, countable] the act of forming opinions about what has happened or what might happen without knowing all the facts speculation (that…) There was widespread speculation that she was going to resign. His private life is the subject of much speculation. speculation (about/over something) Today's announcement ends months of speculation about the company's future. The president's absence led to speculation over his health. She dismissed the newspaper reports as pure speculation. Our speculations proved right.
- 2[uncountable, countable] speculation (in something) the activity of buying and selling goods or shares in a company in the hope of making a profit, but with the risk of losing money speculation in oil