An Etymological Dictionary of Astronomy and Astrophysics

The branch of mathematics which deals with the properties and relations of numbers using symbols (usually letters of the alphabet) to represent numbers or members of a specified set; the generalization and extension of arithmetic.

Etymology (EN): Algebra, from M.L., from Ar. al jabr “reunion of broken bones,” the first known use in the title of a book by the Persian mathematician and astronomer
Abu Ja’far Mohammad ibn Musa al-Khwarizmi (c780-c850), who worked in Baghdad under the patronage of Caliph Al-Mamun. The full title of the tratise was Hisab al-Jabr w’al-Muqabala “Arithmetic of Completion and Balancing.” → algorithm.

Etymology (PE): Jabr, from Ar. al jabr, as above.