1. (Science: mathematics) That branch of mathematics which treats of the relations and properties of quantity by means of letters and other symbols. It is applicable to those relations that are true of every kind of magnitude.
2. A treatise on this science.
Origin: LL. Algebra, fr. Ar. Al-jebr reduction of parts to a whole, or fractions to whole numbers, fr. Jabara to bind together, consolidate; al-jebr w'almuqabalah reduction and comparison (by equations): cf. F. Algebre, It. & sp. Algebra.