Dr Chuck's Lexicon

ad infinitum:  ad infinitum is a Latin phrase that translates as "forever," "without limit," or "to infinity."

Analytic Statements:  Statements that are true in virtue of the meaning of the constitute terms.  For example, "All unmarried human males are bachelors," is an analytic statement.

Apriori knowledge: Knowledge had prior to, or independent of experience, also called non-empirical knowledge.

Aposteriori knowledge: Knowledge had as a result of or after experience, also called empirical knowledge.

Empirical: Something that can be observed, sensed, or experienced.  

Hedonism: The view that pleasure is the highest or the only human value or goal, and the moral theory that holds that human beings should act in ways that maximize that goal.

Paradox: A paradox is a statement or group of statements that seem true or intuitively obvious, but which imply a contradiction or describe a situation which is intuitively false or impossible.

Prima Facie: Prima facie is a Latin phrase that translates as "at first sight."  In philosophy it generally indicates that an idea, assertion, or course of action is plausible or intuitive initially, though further evidence might show it to be otherwise.

Referential Opacity: Two terms are referentially opaque if they refer to the same object or property, but they cannot be substituted salva veritate (i.e. without changing the truth value of the statement).

Synthetic Statements: Statements the truth or falsity of which can be determined only by observation and experience.

Tautology: A statement which is necessarily true in virtue of its logical structure, i.e., in virtue of the logical relationships between it's elements.  For example, "Either it is raining or it not raining," is a tautology.

Online Dictionaries

A Dictionary of Philosophical Terms and Names

Glossary of Philosophic Terms

Dictionary of the Philosophy of Mind