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

1) To unite or so as to bring about an increase.
2) To increase a number by another number using addition, which leads to a → sum.

M.E. adden, from L. addere "add to, join," from → ad- "to" + -dere combining form meaning "to put, place," from dare "to give, grant," from PIE base *do- "to give" (cf. Av. and O.Pers. dâ- "to give, grant, yield," Av. dadâiti "he gives," Skt. dadâti "he gives," Gk. didomi "I give," L. do "I give").

Bardâyidan, from bar- "on; up; upon; in, into; at; forth," → on-, + O.Pers./Av. dā- "to give, grant, put," dadāiti "he gives;" Mid.Pers./Mod.Pers. dâdan "to give, put" (cf. Skt. dadáti "he gives;" Gk. tithenai "to place, put, set," didomi "I give;" L. dare "to give, offer;" Rus. delat' "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do;" PIE base *dhe- "to put, to do") + -y-, epenthetic vowel, + infinitive suffix -idan.
Afzudan, → increase.

A number or quantity to be added to another. In the expression 5 + 3, both 5 and 3 are addends.

From L. addendus "that which is to be added," → add.

Bardâyé, from present stem bardây-, → add, + noun forming suffix -é.

The operation of combining two or more quantities to obtain a third quantity called their → sum. The result of adding.

Verbal noun of → add.

The → plus sign +. It is believed to be a shortened form of the letters e and t in the L. word et, which, in early German manuscripts was the term for addition. The signs + and - were first used by Johann Wiedmann in 1489.

→ addition; → sign.

1) Involving → addition.
2) Something added to a substance to alter or improve it.

From L. additivus "added, annexed," from p.p. stem of addere, → add; → -ive.

1) Related to bardâyeš, → addition; 2) from bardây- prsent stem of bardâyidan, → add, + -é nuance suffix.

Color created by mixing light rays of different colors. Combining all the color rays of light results in white light. See also → subtractive color.

→ additive; → color.

The number which can be added to any other number without changing the magnitude of that number: zero. → multiplicative identity.

→ additive; → identity.

If E₁, E₂, ..., E_n are n → mutually exclusive events, then the probability of occurrence of at least one of them is the sum of their individual probabilities: P(E₁ + E₂ + ... + E_n) = P(E₁) + P(E₂) + ... + P(E_n).

→ additive; → law; → probability.

→ alpha process.

→ alpha; → ladder.

A spectral line energy distribution which plots the intensity of each → carbon monoxide (CO) transition as a function of the upper J number. This type of → diagram is a powerful diagnostic tool, where models show that these CO ladders have very different shapes depending on the type of excitation (i.e. photon dominated region, PDR or X-ray dominated region, XDR) as well as density and radiation environment.

→ carbon monoxide (CO); → ladder.

An image made up of several individual images of relatively short exposure times which are added together in order to produce a final image of higher quality.

Co-added, from → co- "together" + added p.p. of → add; → image.

Tasvir, → image; hamafzudé from ham- "together", → com-, + afzudé p.p. of afzudan, → add.

The process of adding several usually low-exposure images to create an image having a significantly higher signal/noise ratio.

→ image; → co-; → add.

1) A piece of equipment consisting of a series of bars or steps between two upright lengths of wood, metal, or rope, used for climbing up or down something.
2) A series of ascending stages by which someone or something may progress (OxfordDictionaries.com).

M.E. laddre, O.E. hlæder "ladder, steps" (cognates: M.Du. ledere, O.H.G. leitara, Ger. Leiter), from PIE root *klei- "to lean," → incline.

Nardebân "ladder."