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

same as → decimal number system.

→ decimal; → number; → system.

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.

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

Verbal noun of → decide.

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

→ decide; → -ive.

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

→ de-; → claim.

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

Verbal noun of → declare.

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.

The → inflection of nouns, pronouns, or adjectives for case, number, and gender.

M.E. declenson, declynson (with suffix later assimilated to -sion), from O.Fr. declinaison, from L. declinatio, → declination

→ declination.

1) Angular distance (symbol δ) from the celestial equator. One of the coordinates, with → right ascension, that defines the position of a heavenly body in the equator system. Declination is measured positively (+) north or negatively (-) south of the celestial equator from 0° to 90°.
2) Angle between geographic North and magnetic North (symbol D).

Verbal noun of → decline; → -tion.

The axis to which the telescope tube is fastened in an → equatorial mounting.

→ declination; → axis.

For a telescope with an → equatorial mounting, a graduated circle attached to the → declination axis that shows the → declination to which the telescope is pointing.

→ declination; → circle.

1a) To bend down; slope downward; descend.
1b) Grammar: To → inflect according to the various cases of a noun, adjective, or pronoun.
2) The process of declining; a downward movement; gradual loss or deterioration.

M.E. declinen, from O.Fr. decliner "to sink, decline, degenerate, turn aside," from declinare "to turn away, inflect," from → de- + clinare "to bend," cf. Gk. klinein "to cause to slope, slant, incline," Skt. sri- "to lean," O.Pers. θray-, Av. sray- "to lean," Mod.Pers. kil "bent, inclined, slant," PIE base *klei- "to lean, incline" from which is also derived (Ger. lehnen, E. lean).

Vâkil, from prefix vâ- "away" + kil "bent, crooked, inclined" [Dehxodâ], Mid.Pers. xwahl "bent, crooked" (Mod.Pers. dialectal/colloquial variants kowleh, cowleh, cowl, caval, xohl, xohal, hol), cf. Skt. kûla- "slope, declivity;" PIE base *klei-, as above. → inclination

To convert encoded symbols so that they can be used by the computer or understood by a person. See also → encode and → decrypt.

→ de-; → code.

Vâramzidan, from vâ-, → de-. Ramz bardâštan, from ramz, → code, + bardâštan "to remove, to take," from bar- "on; up; upon; in; into; at; forth; with," → on-, + dâštan "to have; to hold; to posses," → property.

An electronic device that converts audio or video signals into a different form that can be heard or seen correctly.

→ decode; → -er.

The process of translating data or a message from a code into the original language or form. See also → encoding and → decryption.

→ decode; → -ing.

Of a physical force or entity or chemical substance, to separate or break into constituent parts or elements.

From → de- + → compose.

The process or the state of breaking down a physical entity or an organic material.

From → de- + → composition.

To cause to undergo → decompression.

→ de- + → compress.

1) A gradual decrease in surrounding → pressure, especially the controlled decrease in pressure that divers undergo after working in deep water or breathing compressed air.
2) Computers: The restoration of compressed electronic data to their full size.

→ de- + → compression.

A mathematical operation that allows to restore the original input signal, such as an astronomical image or spectrum, to its state before being affected by the → atmospheric turbulence and the → transfer function of the instrument. → convolution.

From → de- + → convolution.