Synonyms for Theoretical:

adj.

academic (adjective)
bookish, learned, pedantic, academic, scholarly, literary, formalistic, erudite.
hypothetical (adjective)
notional, logical, presumed, metaphysical, on paper, suppositional, unearthly, abstract, formularized, speculative, ideational, pure, philosophical, general, transcendent, formalistic, intellectual, vague, in the abstract, unproved, contingent, transcendental, academic, codified, analytical, unsubstantiated, Postulated, problematical, ideal, Instanced, tentative, in theory, conjectural, idealized, assumed, pedantic, imaginative.
immaterial (adjective)
conceptual, unearthly, abstract, immaterial, bodiless, eerie, unworldly, ethereal, unsubstantial, imponderable, spiritual, supernatural, incorporeal, imaginary, impalpable, intangible.
notional (adjective)
notional.
suppositional (adjective)
fantastic, speculative, Prophesied, conjectural, hypothetical, suppositional, imaginary, presumed.
topical (adjective)
topical, thematic, conceptual, subject, axiomatic, hypothetical, basic.

n.

utopian, popular, central, orthodox, nonconformist, deterministic. seemingly, doubtful, unfounded, apparently, alleged, anecdotal, allegedly. ideological (noun)
formalistic, in the abstract, idealized, Instanced, in theory, logical, general, unsubstantiated, ideational, transcendental, in the realm of ideas, intellectual, assumed, tentative, stated as a premise, codified, open to proof, vague, contingent, formularized, Postulated, problematical, philosophical, ideal, on paper, unproved, analytical, imaginative.
theoretical (noun)
conjectural, hypothetical, speculative, abstract, notional, suppositional, pure, supposed, theory-based, a priori, academic, theoretic, technical, suppositious, metaphysical, hypothetic, supposititious, abstractive.

Other synonyms:

utopian, popular, central, orthodox, nonconformist, deterministic. transcendental, ideal. transcendent. ambiguous
doubtful.
Other relevant words:
assumed, analytical, seemingly, anecdotal, suppositious, transcendent, formalistic, tentative, ideational, metaphysical, a priori, kinetic, Postulated, newtonian, dynamic, notional, unfounded, contingent, doubtful, theoretic, imaginative, supposititious, central, transcendental, conjectural, pure, technical, intellectual, supposed, codified, hypothetic, deterministic, unsubstantiated, abstractive, aerodynamics, problematical, vague, utopian, theory-based, calorie, orthodox, in theory, in the abstract, logical, formularized, unproved, nonconformist, idealized, on paper, allegedly, general, astrophysics, apparently, alleged, astrophysicist, mechanics, Instanced, ideal, philosophical, popular, dynamics.

Usage examples for theoretical

  1. Yet in the main purpose of his life and writings, which was to mend and guide public opinion on social and political questions by theoretical treatment- that is, by a logically connected survey of the facts- he was undoubtedly successful, as is shown by the popularity of his two great works on Logic and Political Economy, which became the text- books of higher study on these subjects for a whole generation. – Studies in Literature and History by Sir Alfred Comyn Lyall
  2. Of course there would come a limit, at least a theoretical limit. – Who Goes There? by Blackwood Ketcham Benson
  3. He makes but small pretensions to originality in theoretical matter. – The Grammar of English Grammars by Goold Brown