An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

To gather or collect, often in gradual degrees; heap up (Dictionary.com).

From ac-, → ad-, + → cumulate; → amass.

A device for storing electricity. An electric current is passed between two plates in a liquid. This causes charges (due to electrolysis) in the plates and the liquid. Same as → secondary cell.

From L. accumulator, from accumulare "to heap up," from → ad- "in addition" + cumulare "heap up," from cumulus "heap."

Anbâré, from anbâr-, anbâštan, → amass; âkumgar, from âkumidan, → accumulate.

1) The state or quality of being → accurate.
2) The degree of nearness of a measured value to the standard or known value of the quantity, not to be confounded with → precision. For example, a refrigerator holds a constant temperature of 5.0 °C. A thermometer is used seven times to read the temperature, with the following results: 6.4, 5.1, 6.3, 4.5, 5.3, 6.1, and 4.1. This distribution does not well match the actual temperature, therefore it lacks accuracy, and shows no tendency toward a particular value; it lacks precision, as well.
If the measured temperatures are 4.8, 5.3, 5.1, 5.0, 4.6, 5.2, and 5.0, the mean value is accurate, because it comes close to the actual temperature, but the distribution shows no clear tendency toward a particular value (lack of precision).
Now suppose that the measured temperatures are 6.2, 6.3, 6.1, 6.0, 6.1, 6.3, and 6.2. In this case every measurement is well off from the actual temperature (low accuracy), but the distribution does show a tendency toward a particular value (high precision).
Finally, if the measured temperatures are 5.0, 5.0, 4.8, 5.1, 5.0, 4.9, and 5.0, the distribution is very near the actual temperature each time (high accuracy), and does show a tendency toward a particular value (high precision).
Accuracy is often given to n → significant digits or n → decimal places. For example e = 2.71828 ... = 2.718 is rounded to two four significant figures or three decimal places. → accurate to n significant figures, → accurate to n decimal places.

From L. accuratus "prepared with care, exact," p.p. of accurare "take care of," from ad- "to" + curare "take care of."

Rašmandi, from rašmand, from raš + adjective forming suffix -mand. Raš, from Av. root raz- "to right, correct, arrange;" compare with Skt. raj "to reign, rule, direct," Gk. oregein "to strech out," L. rego "to direct, lead;" PIE *reg- "to move in a straight line." Similarly, Av. râšta-, rašta- "straight," Skt. rju "straight, right, upright," Gk. orektos "elongated," L. rectus "straight," Ger. recht, E. right. In Mod.Pers. there are several derivatives: râst, râšt (as in afrâšt(an)) "right; true," rasté, rešté, raj, raž, râh, ris, râdé, radé, Lori rezg "row," etc.

1) Conforming exactly to truth or to a standard; free from error.
2) Designating → accuracy.

Accurate, from L. accuratus, → accuracy.

An expression specifying the number of meaningful digits to the right of the → decimal point. For example, e = 2.71828 ... = 2.718 is said to be accurate to three decimal places and 2.72 to two decimal places.

→ accurate; → decimal; → place.

An expression specifying the number of meaningful digits used to express the value of a measured quantity. Same as accurate to n significant figures. For example, e = 2.71828 ... = 2.718 is rounded to four significant digits, and 2.72 to three significant digits. → accurate to n decimal places.

→ accurate; → significant; → digit.

Able to be accused; open to an accusation (of); blameworthy, reprehensible (OxfordDictionaries.com).

→ accuse; → -able.

A charge or claim that someone has done something illegal or wrong; the action or process of accusing someone (OxfordDictionaries.com).

→ accuse; → -tion.

1) → accusative case.
2) → accusatory.

M.E., from M.Fr., from L. accusativus, from ac-, → ad-, + -cusativus, combining form of causativus, → causative, a loan-translation of Gk. aitiatike, in the sense of pointing to the origin or cause, accusing.

1) Kondâri, i.e. → objective case.
2) → accusatory.

The → grammatical case of a noun in some languages (such as Greek, Latin, G erman, Russian, Old Persian, Avestan, or Sanskrit), which shows that the noun is the → direct object of a → verb or a → preposition.

→ accusative; → case.

Containing an accusation; accusing (Dictionary.com).

→ accuse; → -tion.

To charge with the fault, offense, or crime (Dictionary.com).

M.E. ac(c)usen, from O.Fr. acuser "to accuse, indict, blame," earlier "announce, report, disclose," from L. accusare "to call to account," from → ad- "to, toward, at, with regard to" + causari "give as a cause or motive," from causa "reason," → cause.

Mârzidan, from (Lâr, Gerâsh) mârz, (Farâmarzân) morz "blame, reproach, accusation," maybe ultimately from Proto-Ir. *marc- "to destroy, damage;" cf. Av. mərənc- "to destroy," (+ *para-) "to damage, injure," (+ *ui-) "to ruin, spoil;" Mid.Pers. mwlncyn- / murnjên- "to destroy;" Khotanese mulch- "to cause to miscarry" (Cheung 2007).

A person or persons charged in a court of law with a crime, offense, etc.

→ accuse; → -tion.

A person who accuses, especially in a court of law.

→ accuse; → -tion.

The brightest star in the constellation → Eridanus. A → subgiant of → spectral type B5; apparent visual magnitude 0.5, about 140 → light-years distant (other names: HR 472, HD 10144). Recent interferometric observations show it to have a flattened shape imposed by fast rotation.

Achernar, from Ar. Axir an-Nahr "end of the river," from axir "end" + nahr "river".

Âxer-e nahr, from Axir an-Nahr.
Rudpâyân "river's end," from rud "river," → Eridanus, + pâyân "end".

A class of → stony meteorites that lack → chondrules. They are made of rock that has crystallized from a molten state. Achondrites are relatively rare, accounting for about 8% of all meteorite falls.

Achondrite, from Gk. prefix a- (an- before stems beginning with a vowel or h) "not, without, lacking" + Gk. chondrite, from chondr-, from chondros "grain," + affix -ite.

Of or relating to an optical system which is capable of transmitting light without decomposing it into constituent colors.

→ a-; → chromatic.

Lens (or combination of lenses) that brings different wavelengths within a ray of light to a single focus, thus overcoming chromatic aberration.

→ achromatic; → lens.

A substance that releases hydrogen ions to form a solution with a pH of less than 7, reacts with a base to form a salt, and turns blue litmus red.

From Fr. acide, from L. acidus "sour," adj. of state from acere "to be sour," acer "sharp, pungent, bitter;" from PIE base *ak- "sharp, pointed."

Being or containing an acid; of a solution having an excess of hydrogen atoms (having a → pH of less than 7).

→ acid; → -ic.