late 14c., "praise" (a sense now obsolete), from Old French aloance "sanction, granting, allocation," from aloer "allot, apportion, assign" (see allow). As with allow, the English word involves senses of two different French words.
The meaning "sanction, approval, tolerance" is from 1550s. The sense of "a sum allotted to meet expenses" is from c. 1400. In accounts, the meaning "a sum placed to one's credit" is attested from 1520s. The mechanical meaning "permissible deviation from a standard" is from 1903. To make allowances is to add or deduct a sum from someone's account for some special circumstance; figurative use of the phrase is attested from 1670s.
early 14c., allouen, "to commend, praise; approve of, be pleased with; appreciate the value of;" also, "take into account or give credit for," also, in law and philosophy, "recognize, admit as valid" (a privilege, an excuse, a statement, etc.). From late 14c. as "sanction or permit; condone;" in business, of expenses, etc., by early 15c.
The Middle English word is from Anglo-French alouer, Old French aloer, alloiier (13c.) "to place, situate, arrange; allot, apportion, bestow, assign," from Latin allocare "allocate" (see allocate). This word in Old French was confused and ultimately merged with aloer; alloer "to praise, commend, approve," from Latin allaudare, adlaudare, a compound of ad "to" (see ad-) + laudare "to praise" (see laud).
Between the two primary significations there naturally arose a variety of uses blending them in the general idea of assign with approval, grant, concede a thing claimed or urged, admit a thing offered, permit, etc., etc. [OED].
From the first word came the sense preserved in allowance "money granted;" from the second came allowance "permission based on approval." The 19c. U.S. colloquial meaning "assert, say," also was in English dialect and goes back to 1570s. Related: Allowed; allowing.
c. 1300, "enduring of hardship, affliction, etc.," also "allowance of wrongdoing," from Old French suffrance, from Late Latin sufferentia, from sufferens, present participle of sufferre "to bear, undergo, endure" (see suffer).
"allowance on goods sold by weight," c. 1500, of unknown origin; perhaps related to trait "act of drawing."
1650s, "an allowance by way of discount, deduction from a sum of money to be paid," from rebate (v.). By 1882 as "a repayment, money paid back."
"one in receipt of a pension or regular allowance," late 15c., from Anglo-French pensionner, from Old French pensionnier (mid-14c.), from Medieval Latin pensionarius, from pension "a payment" (see pension (n.)).
1550, "the mental process of reasoning," later, "the relation of one number to another" (1660s), then "fixed allowance of food or other means of subsistence for a fixed period of time" (1702, often rations, from French ration in this sense).
All are from Latin rationem (nominative ratio) "reckoning, numbering, calculation; business affair, procedure," also "reason, reasoning, judgment, understanding," in Medieval Latin "a computed share or allowance of food." This is from rat-, past participle stem of reri "to reckon, calculate," also "think" (from PIE root *re- "to reason, count").
The first sense listed for the English word is obsolete; the second has gone with ratio. The military pronunciation (rhymes with fashion) took over in English from the preferred civilian pronunciation (rhymes with nation) during World War I. That war also gave the word a specific sense of "officially limited allowance for civilians in times of war or dearth" (by 1917).
c. 1300, "household allowance of any kind (food, provisions, clothing) to retainers or servants," from Anglo-French livere (late 13c.; Old French liveree, Modern French livrée), "allowance, ration, pay," originally "(clothes) delivered by a master to his retinue," from fem. past participle of livrer "to dispense, deliver, hand over," from Latin liberare "to set free" (see liberate).
The sense later was reduced to "servants' rations" and "provender for horses" (mid-15c.). The former led to the meaning "distinctive clothing given to servants" (early 14c.); the latter now is obsolete, unless livery stable (1705) survives. Related: Liveried.