Republican \Re*pub"lic*an\ (-l?-kan), a. [F. r['e]publicain.]

1. Of or pertaining to a republic.

The Roman emperors were republican magistrates named by the senate. --Macaulay.

2. Consonant with the principles of a republic; as, republican sentiments or opinions; republican manners.

Republican party. (U.S. Politics)
   (a) An earlier name of the Democratic party when it was opposed to the Federal party. Thomas Jefferson was its great leader.
   (b) One of the existing great parties. It was organized in 1856 by a combination of voters from other parties for the purpose of opposing the extension of slavery, and in 1860 it elected Abraham Lincoln president.

Source: Webster's Revised Unabridged Dictionary (1913)