Algebra carries the Arabic definite article al- on its front, like alcohol and alkali, and behind it lies a word about mending. The source is al-jabr, "the reunion of broken parts" — in mathematics, the step of restoring fractions to whole numbers while solving an equation. It comes from the title of a ninth-century treatise by the Baghdad mathematician al-Khwarizmi, whose book on "calculation by restoring and balancing" reached the West in a twelfth-century Latin translation and brought Arabic numerals with it.
English took the word in the 1550s, and for a while it led a double life: in the fifteenth and sixteenth centuries algebra could also mean bone-setting, which is the same "reuniting broken parts" sense applied to limbs rather than equations — a usage probably picked up from Arab physicians in Spain. The stress moved from the second syllable to the first during the 1600s, giving the modern pronunciation.
algebra
(n.)
"formal mathematics; the analysis of equations; the art of reasoning about quantitative relations by the aid of a compact and highly systematized notation," 1550s, from Medieval Latin
algebra
, from Arabic
"al-mukhtasar fi hisab al-jabr wa al-muqabala"
("the compendium on calculation by restoring and balancing"), the title of the famous 9c. treatise on equations by Baghdad mathematician Abu Ja'far Muhammad ibn Musa al-Khwarizmi.
Arabic
al jabr
("in vulgar pronunciation,
al-jebr
" [Klein]) "reunion of broken parts" (reducing fractions to integers in computation) was one of the two preparatory steps to solving algebraic equations; it is from Arabic
jabara
"reintegrate, reunite, consolidate." Al-Khwarizmi's book (translated into Latin in 12c.) also introduced Arabic numerals to the West.
John Dee (16c.) calls the work
algiebar and almachabel
. The accent shifted 17c. from second syllable to first. The same word was used in English 15c.-16c. to mean "bone-setting," as was Medieval Latin
algebra
, a usage picked up probably from Arab medical men in Spain.
also from 1550s
algebra came in through Later and wider borrowings, and its spelling follows that family's conventions.
How that family writes these sounds
| a technical noun about maths, chemistry, or the stars | Arabic: al- welded onto the front, article and allalgebra, algorithm, alcohol, almanac |
What gives it away on the page
| al- fused to the front of the noun | Arabic, usually via Spanish or Latin — al is the article, stuck on permanently.alcohol, algebra, algorithm, alkali, almanac, admiral |
Placing it without the spelling
| mathematics, chemistry, the stars | Arabic, through Spanish or Latinalgebra, algorithm, alcohol, almanac |
Later and wider borrowings in the spelling guide · guess another word's family