1610s, "act of growing by organic enlargement;" 1650s as "that which is formed by continued growth from without," from Latin accretionem (nominative accretio) "an increasing, a growing larger" (as of the waxing moon), noun of action from past-participle stem of accrescere "grow progressively, increase, become greater," from ad "to" (see ad-) + crescere "grow" (from PIE root *ker- (2) "to grow"). It goes with the verb accrue. Related: Accretional; accretionary.

formerly also accrew, mid-15c., acreuen, in reference to property, etc., "to fall to someone as an addition or increment," from Old French acreue "growth, increase, what has grown," fem. of acreu, past participle of acreistre (Modern French accroître) "to increase," from Latin accrescere "grow progressively, increase, become greater," from ad "to" (see ad-) + crescere "grow" (from PIE root *ker- (2) "to grow"). Related: Accrued; accruing.

Apparently an English verb from a French noun because there is no English noun to go with it until much later (the earliest seems to be now-obsolete accrue, 1570s), unless the record is defective. From late 15c. as "happen or result as a natural growth;" from 1881 as "gain by increment, accumulate." Alternative verb accrete "grow by adhesion" (1784) is rare, as is accresce (1630s), from Latin accrescere.

"long, powerful horn," formerly used to convey messages across valleys, 1864, from German, literally "horn of the Alps;" see Alp + horn (n.).

ancient zodiac sign represented as a goat, or half-goat half-fish, late Old English, from Latin Capricornus, literally "horned like a goat," from caper (genitive capri) "goat" (see cab) + cornu "horn" (from PIE root *ker- (1) "horn; head").

A loan-translation of Greek Aigokherōs, a name of the constellation, the "horned goat" to distinguish it from "the kids" in Auriga, a popular asterism sometimes regarded by the Romans as a separate constellation. The common Latin name was simply "goat" (caper, hircus). It was naturally associated in Rome with the goat Amalthea that nursed the infant Zeus, and thus with the image in cornucopia, which also emphasizes the horn. Allen ("Star Names and Their Meanings") reports the Anglo-Saxons knew it as both bucca and buccan horn.

Extended 1894 to persons born under the sign.

also karat, late 15c., "a measure of the fineness of gold," from Old French carat "measure of the fineness of gold" (14c.), from Italian carato or Medieval Latin carratus, both from Arabic qirat "fruit of the carob tree," also "weight of 4 grains," from Greek keration "carob seed," also the name of a small weight of measure, literally "little horn" diminutive of keras "horn of an animal" (from PIE root *ker- (1) "horn; head").

Carob beans were a standard in the ancient world for weighing small quantities. The Greek measure was the equivalent of the Roman siliqua, which was one-twenty-fourth of a golden solidus of Constantine; hence karat took on a sense of "a proportion of one twenty-fourth, a twenty-fourth part," especially in expressing the fineness of gold when used as jewelry, and thus it became a measure of gold purity (1550s): 18-carat gold is eighteen parts gold, six parts alloy; 14-carat gold is 10/24ths alloy, etc.

As a measure of weight for diamonds or other precious stones, carat is attested from 1570s in English. In U.S., karat is used for "proportion of fine gold in an alloy" and carat for "measure of weight of a precious stone."

non-metallic element occurring naturally as diamond, graphite, or charcoal, 1789, coined 1787 in French by Lavoisier as charbone, from Latin carbonem (nominative carbo) "a coal, glowing coal; charcoal," from PIE root *ker- (3) "heat, fire."

Carbon 14, the long-lived radioactive isotope used in dating organic deposits, is from 1936. Carbon-dating (using carbon 14) is recorded from 1958. Carbon cycle is attested from 1912; carbon footprint was in use by 2001. Carbon-paper "paper faced with carbon, used between two sheets for reproduction on the lower of what is drawn or written on the upper" is from 1855, earlier it was carbonic paper (1850).

1799, "coal-bearing, containing or yielding carbon or coal," from Latin carbo (genitive carbonis) "coal" (see carbon) + -ferous "producing, containing, bearing," from ferre "to bear" (from PIE root *bher- (1) "to carry," also "to bear children").

It was used in designating the rocks which formed the great coal-beds of England, France, Germany and the United States; from 1832 with reference to the geological period when these were laid down. As a stand-alone noun (short for Carboniferous Period) by 1907.

early 13c., "fiery jewel, gem of a deep red color, ruby," also the name of a semi-mythical gem from the East Indies formerly believed to be capable of shining in the dark, from Old North French carbuncle (Old French charbocle, charboncle) "carbuncle-stone," also "carbuncle, boil," from Latin carbunculus "red gem," also "red, inflamed spot," literally "a little coal," from carbo (genitive carbonis) "coal" (see carbon).

Originally of rubies, garnets, and other red jewels. In English the word was used of red, eruptive subcutaneous inflammations and tumors from late 14c. Also "red spot on the nose or face caused by intemperance" (1680s).

orange-colored hydrocarbon found in carrots and other plants, 1861, from German carotin, coined 1831 by German chemist H.W.F. Wackenroder (1789-1854) from Latin carota "carrot" (see carrot) + German form of chemical suffix -ine (2), denoting a hydrocarbon.

1540s, "pertaining to the two great arteries of the neck," from Greek karotidēs "great arteries of the neck," plural of karotis, from karoun "plunge into sleep or stupor," because compression of these arteries was believed to cause unconsciousness (Galen). But if this is folk etymology, the Greek word could be from kara "head," related to kranion "skull, upper part of the head" (from PIE root *ker- (1) "horn; head").