<p><strong>Adverb</strong></p><ul><li>In principle; according to reasonable assumptions or rules, as opposed to what actually happens: Theoretically they are free to work, but in practice they can’t because we do not recognize their credentials.</li><li>In a way that is purely speculative; hypothetically: It seems that theoretically the central bank could constrain government spending by allowing treasury checks to bounce.</li><li>According to, or in a way that relates to, a scientific theory: An alloy with a particular composition can be modeled to determine theoretically whether it has suitable mechanical and physical properties for medical applications.</li><li>In a way that relates to the set of principles or methods belonging to a particular subject, art, or activity: Taking classes in all four fields—politics, economics, history, and culture—allows students to be grounded theoretically in the humanities and social sciences.</li></ul>