The origin of the word "algebra" is intriguing because it has no clear etymology or derivation of another word. Algebra is a Latin variant of the Arabic word al-jabr, used in the title of a book, *Hisab al-jabr w'al-muqabalah*, written in Baghdad around the year 825 by the Arabic mathematician Mohammed ibn-Musa al Khowarizmi. This work of algebra is often referred to briefly as Al-jabr.

In it, the term al-jabr refers to the operation of transposing an amount subtracted from one side of an equation to the other side, where it becomes an aggregate quantity. Al-muqâbalah refers to the reduction of a positive term by subtracting equal amounts from both sides of the equation.

The word al-jabr means "reunion of broken parts". When the Moors took the word al-jabr to Spain, an algebraist became a "restorer," the one who restores broken bones. So in the work *Don Quixote*mentions "an algebraist who met Samson's misfortune". The Oxford dictionary also quotes from a 1541 book on surgery: "The Aids to Algebra and Dislocations."

Around 1140, when Robert de Chester translated al-Khowarizmi's work into Latin, the words in the title were not translated, and the Arabic words were borrowed, leaving the title. *Liber algebrae and almucabala*.

It was even believed that the word algebra derived from the name Gabir ben Allah of Seville, commonly called Geber, a well-known astronomer apparently skilled in algebra. Joseph Raphson's mathematical dictionary (1702) quotes: "Al's Algebra in Arabic, which means excellent, and Geber, the name of the alleged inventor." This etymology is not entirely absurd, though it is but an assumption.

Al-Khowarizmi algebra was the name of an operation used in solving an equation, but in 1600 the word was applied to the study in which this operation was used. Already in the 19th and 20th centuries, the word algebra took on other meanings, either to mean a formal calculation or to identify some specific constructions, such as boolean algebra and set algebra.