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

A nuclear reactor designed for radionuclide production, materials testing, and training.

→ research; → reactor.

A scientist who devotes himself to doing research.

Agent noun, from → research + → -or.

A grid of fine lines photographed onto or cut into a glass plate and used as a reference for astronomical observations.

From Fr. réseau, O.Fr. reseuil "little net," from raiz "net," from L. rete "net."

Rezo, loan from Fr., as above.

To dwell permanently or for a considerable time.

M.E., from M.Fr. resider and directly from L. residere "sit down, settle; remain behind, rest," from → re- "back, again" + sedere "to sit," cognate with Pers. nešastan "to sit down," as below.

Neštidan, from Baluci ništ-, Kurd. ništin, Gurani nîšt, Awromani ništay-, Gazi ništ, Shahmerzadi -ništ, Gilaki ništoen "to sit down," variant of Pers. nešastan "to sit down, settle down," nešim "nest," Mid.Pers. nišastan "to sit;" O.Pers. nišādayam [1 sg.impf.caus.act.] "to sit down, to establish," hadiš- "abode;" Av. nišasiiā [1 sg.subj.acr.] "I shall sit down," from nihad- "to sit down," from → ni- "down, below," + had- "to sit;" PIE base *sed- "to sit;" cf. Skt. sad- "to sit," sidati "sits;" Gk. hezomai "to sit," hedra "seat, chair;" L. sedere "to sit;" O.Ir. suide "seat, sitting;" Welsh sedd "seat;" Lith. sedmi "to sit;" Rus. sad "garden;" Goth. sitan, Ger. sitzen; E. sit.

1) The place, especially the house, in which a person lives or resides; dwelling place; home.
2) The act or fact of residing (Dictionary.com).

→ reside; → -ence.

Neštgâh, from nešt present stem of neštidan→ reside + -gâh a suffix of place and time. Neštmân with -mân a suffix of verbl nouns used with present and past stems, as in zâymân, câymân, sâxtemân, sâzmân, goftemân, râžmân.

A person who resides in a place.

→ reside + -ent, a suffix, equivalent to -ant froming nouns and adjectives.

Of, relating to, or remaining as a residue; leftover.

→ residue; → -al.

The magnetic field left in an iron core after excitation has been removed.

→ residual; → field.

1) General: Something that remains after a process involving the removal of part of the original has been completed.
2) Math.: If f(z) is a → complex function, its residue at an isolated → singularity  z₀ is defined by the → integral (1/2πi) ∫f(z)dz taken along a simple closed curve interior to an annulus about z₀.

M.E., from O.Fr. residu, from L. residuum "a remainder," neuter of residuus "remaining, left over," from residere "to remain behind."

Munak, from mun-, dialectal variant of mân-/mândan "to remain" (e.g., Farizani mundä, Gazi mun-, Khunsâri mûn-, Natanzi, Semnâni -mund, Yghnobi mun-), Mid.Pers. mân-/mândan "to remain, to stay;" O.Pers. mān "to remain, dwell;" Av. mān- "to remain, dwell;" cognate with E. → remain; + relation/diminution suffix -ak.

The theorem stating that the value of the line integral of a complex function, taken along a simple closed curve encircling a finite number of isolated singularities, is given by 2πi times the sum of the residues of the function at each of the singularities.

→ residue; → theorem.

To give up an office or position, often formally.

M.E. resignen "give up, surrender, abandon; relinquish," from O.Fr. resigner "renounce, relinquish," from L. resignare "to check off, cancel, give back, give up," from → re- "opposite" + signare "to make an entry in an account book," literally "to mark;" → sign.

Vâgâmidan, literally "to step back," from vâ-→ re- + gâmidan "to step, go, → walk."

The act of resigning.

Verbal noun from → resign.

To withstand the action or effect of; to strive against, or oppose.

M.E. resisten, O.Fr. resister, from L. resistere "to resist, to stand back, withstand," from → re- "against" + sistere "take a stand, stand firm," cognate with Pers. istâdan, as below.

Baristâdan "to withstand, to stand in opposition," from bar- opposition prefix, → object, + istâdan "to stand," → solstice.
Istâdegi kardan, composite verb, from istâdegi "resistance," state noun from istâdan, + kardan "to do, to make," → -or.

1) General: The act or power of resisting, opposing, or withstanding.
2) Electricity: A property of a conductor by virtue of which the passage of current is opposed, causing electric energy to be transformed into heat. It is the quantity that determines the current that results due to a voltage in a simple circuit. For a fixed voltage, if the resistance increases, the current decreases. It is given by the equation R = ΔV/I, where ΔV is the voltage difference and I the current. Resistance has the SI units volts per ampere, called → ohm.

From → resist + -ance a suffix used to form nouns either from adjectives in -ant or from verbs.

Baristgari, from baristgar, → resistant.
Istâdegi "resistance," state noun from istâdé "stood," p.p. of istâdan "to stand," → resist.

1) Characterized by or showing resistance.
2) A person or thing that resists.

Present participle of → resist, with -ant a suffix forming adjectives and nouns from verbs.

Baristgar, from barist present stem of baristâdan, → resist, + -gar, agent suffix, → -or.
Istâdegigar, from istâdegi, → resistance, + -gar.

Capable of or inclined to resistance; resisting.

From resist, → resistance, + → -ive.

Baristmand, from barist present stem of baristâdan, → resist + -mand possession suffix, → -ist.

A property of a → conductor which is defined as the ratio of the → electric intensity (E) to the → current density (J): ρ = E/J. The greater the resistivity, the greater the intensity needed to establish a given current density, or the smaller the current density for a given intensity. A "perfect" conductor would have zero resistivity, and a "perfect" → insulator an infinite resistivity.

From → resistive + → -ity.

An electrical component used to introduce a known value of resistance into a circuit.

→ resist; → -or.

1) The degree to which an → optical system renders visible separate parts of an object. Also known as → angular resolution and → spatial resolution. See also → spectral resolution.
2) The time interval between successive discernible signals. → temporal resolution.

Verbal noun of → resolve.

Finding the → components of a → force which act in specified → directions.

→ resolution; → force.