theoretical

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Of, relating to, or based on theory.
2. adj. Restricted to theory; not practical: theoretical physics.
3. adj. Given to theorizing; speculative.

Century Dictionary and Cyclopedia

1. In chem., indicating the analytical values or other properties which should be obtained from a compound provided the correct conception (theory) of its composition has been formed.
2. Having the object of knowledge (θεωρητόν) as its end; concerned with knowledge only, not with accomplishing anything or producing anything; purely scientific; speculative. This is the original, proper, and best meaning of the word. Aristotle divides all knowledge into productive (art) and unproductive (science), and the latter into that which aims at accomplishing something (practical science) and that which aims only at understanding its object, which is theoretical science. This distinction, which has descended to our times (but with practical science and art joined together), diminishes in importance as science advances, all the sciences finding practical applications.
3. Dealing with or making deductions from imperfect theory, and not correctly indicating the real facts as presenting themselves in experience. All the practical sciences that have been pursued with distinguished success proceed by deductions from hypotheses known not to be strictly true. This is the analytical method, of which modern civilization is the fruit. In some cases the hypotheses are so far from the truth that the results have to receive corrections. In such cases the uncorrected result is called theoretical, the corrected result practical.
4. In Kantian terminology, having reference to what is or is not true, as opposed to practical, or having reference to what ought or may innocently be done or left undone.

Wiktionary

1. adj. Of or relating to theory; abstract; not empirical.

WordNet 3.0

1. adj. concerned primarily with theories or hypotheses rather than practical considerations
2. adj. concerned with theories rather than their practical applications