Postulate

POS'TULATE, n. [L. postulatum, from postulo, to demand, from the root of posco, to ask or demand. The sense is to urge or push.]
A position or supposition assumed without proof, or one which is considered as self-evident, or too plain to require illustration.
A self-evident problem, answering to axiom, which is a self-evident theorem.
POS'TULATE, v.t. [supra.] To beg or assume without proof. [Little used.]
1. To invite; to solicit; to require by entreaty.
2. To assume; to take without positive consent.
The Byzantine emperors appear to have exercised, or at least to have postulated a sort of paramount supremacy over this nation.

NEW: Google Full-Text Search of Webster's 1828 Custom Search Search Webster's 1828 Advanced Search

You can also look up words at dict.sorabji.com