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

The → number of → vertices.

→ order; → graph.

The maximum number of the indices (→ index) of a tensor.

→ order; → tensor.

A whole number which characterizes a particular position of an interference fringe according to whether there is interference arising from one, two, three, etc. wavelength difference of path. Same as → interference order

→ order; → interference.

Value of a number or of a physical quantity given roughly, usually expressed as a power of 10. Thus, 2.5 x 10⁵ and 6.4 x 10⁵ are of the same order of magnitude, and 2 x 10⁷ is 2 orders of magnitude greater than either.

→ order; → magnitude.

Characterized by → order; arranged according to a rule. → ordered tree.

→ order + -ed.

In → graph theory, a → tree in which the → children of each → vertex are ordered.

→ ordered; → tree.

1) Of or relating to an order, as of animals or plants.
2) Of or relating to order, rank, or position in a series.
3) → ordinal number.

M.E., from O.Fr., from L.L. ordinalis "denoting order or place in a series," from L. ordo (genitive ordinis) "row, series," → order; → -al.

→ order; → -al.

1) A number which defines the position or rank of something in a series, in contrast to → cardinal number. For example, first, second, tenth, etc.
2) In → set theory, the order type of a → well-ordered set. Also called ordinal.

→ ordinal; → number.

Usual; normal. → ordinary ray; → ordinary year.

M.E. ordinarie, from O.Fr. ordinarie, from L. ordinarius "regular, usual, orderly," from ordo (genitive ordinis) "order" + -arius-ary.

Šunik "ordinary," from Mid.Pers. šônik, šônig "ordinary, customary," from šôn "kind, manner, sort, way" + -ik, → -ic.

A → differential equation in which the unknown function depends on only one → independent variable, as contrasted with a → partial differential equation.

→ ordinary; → differential; → equation.

The point M₀(x₀,y₀) of the curve F(x,y) = 0, where at least one of the partial derivatives ∂F/∂x and ∂F/∂y does not vanish. → singular point

→ ordinary; → point.

The ray that has an → isotropic speed in a → doubly refracting crystal. It obeys → Snell's law upon refraction at the crystal surface. See also → extraordinary ray

→ ordinary; → ray.

A → calendar year that contains 365 days and therefore is not a → leap year.

→ ordinary; → year.

Math.: In plane Cartesian coordinates, the distance of a point from the x-axis measured parallel to the y-axis. → abscissa.

Ordinate, from N.L. (linea) ordinate (applicata) "(line applied) in order;" from ordinatus "arranged."

Ârâ, from ârâstan "to arrange, to set in order, adorn," Mid.Pers. ârây-, ârâstan "to arrange, adorn;" O.Pers. rās- "to be right, straight, true," rāsta- "straight, true" (Mod.Pers. râst "straight, true"), rād- "to prepare;" Av. rāz- "to direct, put in line, set," razan- "order;" Gk. oregein "to stretch out;" L. regere "to lead straight, guide, rule," p.p. rectus "right, straight;" Skt. rji- "to make straight or right, arrange, decorate;" PIE base *reg- "move in a straight line."

A natural deposit containing a mineral of an element to be extracted.

Ore, merger of M.E. ore, O.E. ora "ore, unworked metal" and M.E. or(e) "ore, metal," O.E. ar "brass, copper, bronze" (cf. O.N. eir "brass, copper;" Ger. ehern "brazen;" Erz "oar;" Goth. aiz "bronze;" O.H.G. ēr "ore"), from PIE *aus- "gold;" cf. Mod/Mid..Pers. âhan "iron;" Av. aiianhaēna- "made of metal," from aiiah- "metal;" Skt. áyas- "iron, metal;" L. aes "brass"

Kâné, from kân "mine," from kandan "to dig" (Mid.Pers. kandan "to dig;" O.Pers. kan- "to dig," akaniya- "it was dug;" Av. kan- "to dig," uskən- "to dig out" (→ ex- for prefix us-); cf. Skt. khan- "to dig," khanati "he digs").

1) Biology: A structure consisting of tissues and performing some specific function in an organism, e.g. the heart, kidneys, liver, stomach.
2) A large musical keyboard instrument producing a wide range of musical effects using compressed air passed through pipes.
3) An organization or body acting on behalf of a larger institution.
4) A newspaper or magazine regarded as a means of communication, especially one communicating the views of a particular group such as a political party.

O.E. organe, from O.Fr. orgene "musical instrument," from L. organa, pluriel of organum, from Gk. organon "implement, musical instrument, organ of the body," literally "that with which one works," from PIE *werg-ano-, from base *werg- "to do, to work" related to Gk. ergon "work" (cf. Av. varəz- "to work, do, perform, exercise;" Mod.Pers. varz-, varzidan "to labor, exercise, practise;" Arm. gorc "work;" Lith. verziu "tie, fasten, squeeze," vargas "need, distress;" Goth. waurkjan; O.E. wyrcan "work," wrecan "to drive, hunt, pursue").

1) Andâm, from Mid.Pers. handam "member, limb;" Av. handāma- "limb;" from Proto-Iranian *ham-dāman-, from prefix ham-→ com- + *dāman- "created;" Av. dā- "to give, grant; to put; to create; to determine" (O.Pers./Av. dā- "to give, grant, yield," dadāiti "he gives;" Mod.Pers. dâdan "to give;" cf. Skt. dadáti "he gives;" Gk. tithenai "to place, put, set," didomi "I give;" L. dare "to give, offer," facere "to do, to make;" Rus. delat' "to do;" O.H.G. tuon, Ger. tun, O.E. don "to do;" PIE base *dhe- "to put, to do"); cf. Skt. sandháy- "joint, articulation."
2), 3), 4) loanwords from Fr., as above.

1) Of, relating to, or derived from living organisms: organic matter.
2) Characterized by the systematic arrangement of parts; organized; systematic.
3) Chemistry: Of or designating carbon compounds.

From L. organicus, from Gk. organikos "of or pertaining to an organ," from organon "instrument," → organ, + → -ic.

1) Orgânik, loan from Fr.; âli loan from Ar.; 2) sâzmândâr, from sâzmân, → organization, + dâr "having, possessor" (from dâštan "to have, to possess," Mid.Pers. dâštan, O.Pers./Av. root dar- "to hold, keep back, maitain, keep in mind," Skt. dhr-, dharma- "law," Gk. thronos "elevated seat, throne," L. firmus "firm, stable," Lith. daryti "to make," PIE *dher- "to hold, support").

The study of compounds that contain carbon chemically bound to hydrogen.

→ organic; → chemistry.

A molecule that is normally found in or produced by living systems. Organic molecules typically consist of carbon atoms in rings or long chains, where other atoms (e.g. hydrogen, oxygen, and nitrogen) are attached, except for → carbon monoxide (CO) and → carbon dioxide (CO₂), etc.

→ organic; → molecule.

1) Biology: A living individual composed of mutually interdependent parts that maintain various vital processes.
2) Any organized body or system conceived of as analogous to a living being. → microorganism

From → organ + -ism a suffix appearing in loanwords from Gk. denoting several senses, among which state or condition, principles, doctrines.

Sâzvâré, from sâz present stem of sâxtan, sâzidan "to build, make, fashion; to adapt, adjust, be fit" (from Mid.Pers. sâxtan, sâz-, Manichean Parthian s'c'dn "to prepare, to form;" Av. sak- "to understand, to mark," sâcaya- (causative) "to teach") + -vâré, from -vâr a suffix meaning "resembling, like" (from Mid.Pers. -wâr; Av. -vara, -var; cf. Skt. -vara).