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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

   Homepage   
   


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

<< < D l dar dat de deb dec dec dec def deg del dem dep der det deu di- dif dif dif dio Dir dis dis dis dis dis div doo dou dra dua dus dyn dyn > >>

Number of Results: 692
deceleration
  واشتاب   
vâšetâb (#)

Fr.: décéleration   

The act or process of moving, or of causing to move, with decreasing speed. Sometimes called negative acceleration.

Verbal noun of decelerate.

deceleration parameter
  پارامون ِ واشتاب   
pârâmun-e vâšetâb

Fr.: paramètre de décéleration   

A parameter designating the rate at which the expansion of the Universe would slow down owing to the braking gravitational effect of the matter content of the Universe. It is expressed by: q(t) = -R(t)R ..(t)/R .2(t), where R(t) represents the size of the Universe at time t. See also → expansion parameter; compare with → acceleration parameter.

deceleration; → parameter.

deci-
  دسی-   
desi- (#)

Fr.: déci-   

Prefix used in the metric system to mean on-tenth.

From Fr. déci-, from L. decimus "tenth," from decem "ten," cf. Av. dasa "ten," Mod.Pers. dah "ten," Gk. deka, Skt. dasa, PIE *dekm (Dan. ti, Du. tien, Ger. zehn, E. ten, Fr. dix).

Desi-, from Fr. déci-, as above.

decibel (dB)
  دسی‌بل   
desibel (#)

Fr.: décibel   

A dimensionless unit used to express relative difference in power or intensity, usually between two acoustic or electric signals. It is defined as n [dB] = 10 log (P1/P0), with → natural logarithm. One decibel equals one-tenth of a → bel (B).

deci-; → bel (B).

decide
  واسونیدن   
vâsunidan

Fr.: décider   

To make a choice or come to a conclusion about something. → decision, → rule of decision.

M.E. deciden, from O.Fr. decider, from L. decidere "to decide, determine," literally "to cut off," from → de-"off" + caedere "to cut, chop, beat, hew."

Vâsunidan, from vâ- "off, away," → de-, + sun "to cut;" cf. Kurd. Soriani su, sun "to sharpen, whet;" Kurd. Kurmanji (prefixed ha-, contraction of *ham-) hasun "to sharpen, whet;" Mod.Pers. sân "whetstone," variants fasân, afsân, awsân; Av. si-, sā- "to cut;" cf. Skt. śā- "to sharpen, whet;" + -idan infinitive suffix.

decider
  واسوننده   
vâsunandé

Fr.: décideur   

Someone who decides, or something that allows to determine.

decide; → -er.

decimal
  دهدهی   
dahdahi (#)

Fr.: décimal   

Referring to or based in the number 10; relating to tens or tenths.

M.L. decimalis "of tithes or tenths," from L. decimus "tenth," from decem, → ten.

Dahi , of or relating to dah, → ten; dahdahi literally "ten by ten."

decimal fraction
  برخه‌ی ِ دهدهی   
barxe-ye dahdahi

Fr.: fraction décimale   

A fraction expressed by using → decimal representation, as opposed to a vulgar fraction. For example, 2/5 is a vulgar fraction; 0.40 is a decimal fraction.

decimal; → fraction.

decimal logarithm
  لگاریتم ِ دهدهی   
logâritm-e dahdahi

Fr.: logarithme décimal   

common logarithm.

decimal; → logarithm.

decimal number system
  راژمان ِ عددهای ِ دهدهی   
râžmân-e adadhâ-ye dahdahi

Fr.: système des nombres décimaux   

A system of numerals for representing real numbers that uses the → base 10. It includes the digits from 0 through 9.

decimal; → system.

decimal place
  رقم پس از جداگر، ~ ~ ~ ممیز   
raqam pas az jodâgar, ~ ~ ~ momayez

Fr.: décimale, chiffre après la virgule   

The position of a digit to the right of a → decimal point written in decimal notation. In 0.032, for example, 0 is the first decimal place, 3 is the second decimal place, and 2 is the third decimal place.

decimal; → place.

Raqam, → digit; pas, → after; jodâgar, momayez, → decimal point.

decimal point
  جداگر، ممیز   
jodâgar, momayez (#)

Fr.: séparateur décimal, signe décimal   

A symbol (usually a point or dot) used to separate the integer part from the fractional part of a → decimal number.

decimal; → point.

Jodâgar, → separator.
Momayez, from Ar. mumaiyiz "distinguisher, discerner, separator."

decimal representation
  نمایندگی ِ دهدهی   
nemâyandegi;-ye dahdahi

Fr.: représentation décimale   

A representation of a real number between 0 and 1, as written a = d1d2d3 ..., where each di is one of the digits 0, 1, 2, ..., 9. This means that a = d1 x 10-1 + d2 x 10-2 + d3 x 10-3+ ...

decimal; → representation.

decimal system
  راژمان ِ دهدهی   
râžmân-e dahdahi

Fr.: système décimal   

same as → decimal number system.

decimal; → number; → system.

decimetric wave
  موج ِ دسی‌متری   
mowj-e desimetri (#)

Fr.: onde décimétrique   

An electromagnetic radio wave having wavelengths between 10 cm and 1m, corresponding to a frequency between 300 and 3,000 Mega Hertz. It is naturally emitted by various astronomical objects.

Decimetric, from → deci- + from Fr. métrique, → metric; → wave.

Mowj, → wave; desimetri, from décimétrique, as above.

decision
  واسون   
vâsun

Fr.: décision   

The act or process of deciding. → rule of decision.

Verbal noun of → decide.

decisive
  واسونمند   
vâsunmand

Fr.: décisif   

Having the power or quality of deciding; putting an end to controversy; crucial or most important (Dictionary.com).

decide; → -ive.

declaim
  وازوییدن   
vâzuyidan

Fr.: déclamer   

To speak aloud in an oratorical manner; make a formal speech (Dictionary.com).

de-; → claim.

declaration
  روناگش   
runâgeš

Fr.: déclaration   

The act of declaring; announcement.
2) Something that is announced or proclaimed.

Verbal noun of → declare.

declare
  روناگیدن   
runâgidan

Fr.: déclarer   

1) To make known or state clearly, especially in explicit or formal terms.
2) To announce officially; proclaim (Dictionary.com).

M.E. declaren, from O.Fr. declarer "explain, elucidate," from L. declarare "make clear, reveal, disclose, announce," from → de- intensive prefix + clarare "clarify," from clarus, → clear.

From Kurd. (Sorani) rûnâk, runâg "clear, bright," rûn "bright, clear," rûn kirdin "to explain," variants of rowšanâ, rowšan, rušanâ, → bright, → day.

<< < D l dar dat de deb dec dec dec def deg del dem dep der det deu di- dif dif dif dio Dir dis dis dis dis dis div doo dou dra dua dus dyn dyn > >>