Synonyms for theoretical

ideological, ideal, imaginative, unearthly, idealized, ideational, problematical, analytical, academic, presumed, postulated, assumed, formularized, formalistic, pedantic, codified, technical, intellectual, vague, abstract, general, conjectural, unproved, tentative, suppositional, pure, unsubstantiated, speculative, transcendental, philosophical, logical, metaphysical, contingent, instanced, open to proof, stated as a premise, in theory, on paper, in the abstract, in the realm of ideas; see also hypothetical 1.

Antonyms practical*, applied, factual.